Why? Decay.

Not Ignorance

Many very good people, who understand that they are not standalone entities who just appeared but part of some type of a process/system that can be ideologically considered genetic-related (that can be called "a chain of being") have been deceived.  Compare this to how "progressives" have been deceived--people who are intelligent and good in many ways, but incredibly, often dangerously, stupid in others.  

This type of deception is extremely powerful.  There are a minority of genuinely evil people who desire destruction and temporary (like, maybe a thousand years "temporary"; very long as to current Earthly humans) badness, either because they were made to cause the decay of societies and/or because they are likely to become the comptrollers of some larger system of skimanagement ("globalists").  

The cultural suicidality often seen in White people is a flattery of self.  It doesn't seem like that, but conceptualize how a White person saying, "White people suck" is complimenting her- or himself.  What they are advocating, if pressed, is the idea that White people have genes strong enough that their predecessors were exploiters rather than the exploited.  It's like the way there is no discussion of reparations for Irish slavery or the potato "famine" etc.  (If you don't know about that one, it's where Harry Potters were we mean the British were actually shipping food from Ireland to Britain while the Irish were starving to death.)  Saying that White people were exploiters rather than exploited, as Europeoids carried out their stupid history of giving away a lot of nice things to other breeding groups is saying, basically, "We wuz kangz."  

In the real world, Europeoids were handing out inventions (irrigation, the participles [language], dams, automobiles, firearms, etc.) to other breeding groups even as other Europeoids were getting massacred, skimanaged, raped, and so forth.  The eerie, suicidal passion for what bad exploiters Europeoids were, when delivered by a Europeoid, is an extreme defense of a person's own genetic coding.  You might view that as a bad decision, but it can be explained: it's self-flattery, and of something so integral to that person--the genes carried by that person--that that person is willing to die believing "I have such strong genes!"  This delusional fantasy persists among Europeoids; many Whites want to believe they wuz kangs so badly that they're willing to die over it.  

(To make the conceptualization easier, imagine some woman with large breasts always wearing a low-cut top and pretending to drop her pen so that people will look at her bending over to pick up the pen.  That is the type of thing Whites who lament the taking of Amerindian ["Native American"] land, the great badness of treating Blacks wrong, an end to Whiteness, etc. are doing: calling attention to how strong are their genes.)  

The majority of globalists are simply deceived.  In an NWO, they would be doing some boring job, working 100 hours a week, bedside prongs poking them every few hours to check their Citimail, and so forth.  

Or, some eager young White woman insisting on refugee policy so that most of her later 20s can be spent not consenting to having a half-dozen new boyfriends per night. 

Neither of these people, obviously, wants such a fate--wants it at all.  Not even a tiny bit.  The end results of their policies can be figured out; it is exceedingly simple, even within the echo-chamber of the popular stories, to find out that the genetic anti-determinism, non-free-economies managed by experts, have produced horrible fates.  

(The White woman advocating for refugees is generally conveying, amongst other things, "I am a meiotic female and the meiotic males more like me are failing to shelter me, so reproductive access to me is open," and, "My genes are so good that they dominated you poor victims with genes not as good as mine."  Again, ironically, even extreme self-harm can be done by someone who is flattering himself.  Some portion of "refugees welcome" are just fictional, i.e. a news organization is told to mention how many voters demand immigration, and some paid actresses, i.e. a very rich organization pays X,000 people to show up doing XYZ.  The drive of Decay to cycle the environment and thus destroy the West is such that the creation of false narratives, such as of course "this special rabbi will give you really nice things when you die," happens.)  

Several large polities in Africa, and several communist countries elsewhere, have demonstrated the repeated again and again utter dearth of communism and Black government free of any possible smidgen of a hairsbreadth of an iota of White racism.  Yet, people who are smart enough to figure these things out fail to.  Why?  

Soul

The foundational untruth of these systems of thought is that the soul is generated by the brain.  What can help you understand that such is not the case is that the cells composing the brain all die out and are replaced, several times, during that person's life (assuming they live north of 60; not that they die a month after birth).  Think about you.  Do you feel like you are you, even though a few thousand of your brain cells might die today and get replaced by these complete newbies?  Besides that change, your brain cells are all coded for apoptosis.  

Evil Dreams

Postulating "evil" as an answer is the end of the road for many.  Others try to theorize that stupid, self-destructive behavior is caused by ignorance.  Terrible things can be avoided if only people become non-ignorant, become un-deceived, about the evil plans of those advocating such.  

There are, though, no victories in the environmental sense.  People cannot--nor should they if they could--stop the environment.  That is why it will never work to change the minds of many people.  Already, people can use the internet for free, acquire a book for free, and find out what happens in countries governed by those not farfathered in the West; what planned economies do.  And yet, people keep feeling--acting like they are completely convinced forever and ever--that planned economies and genetic heterogeneity is good.  

Theories of some motivation for self-harmful behavior have been tried--think of "pathological altruism."  However, like fantasies about pre-Christianization Europe being filled with delusional pagan crazies who worshiped sky-furries, such theories rest upon the notions that:

1) It is bad to hurt yourself; and,

2) You don't want bad things to happen to you.  

Wrong!  It is good for societies to decay, it is good for planets to decay, and it is only within the limited timescales of let's say a few thousand years that such things are seen as bad.  The limiting of timescales expounded by Christianity--various geneses; think of the Book of Genesis or the Big Bang Theory--is depicting upon people--like unto ideologies inflicted onto Europeans once the survivors were subjected to rabbi-worship--something incorrect.  

(What Christianity has anthropocentrically done is make its victims on Earth think time is like a straight line upon which one progresses rather than a circle about which you course.  More later.)

Thought

From where do your thoughts come?  In traditional local narcissistic fashion, it is assumed that they are generated by our brains, just like our senses of self--our consciousness; our soul.  S.R. is the judge of the fate of your soul, and you either get to be with S.R. forever, or if you are a man who just doesn't want to be held by a man, Jesus also created this Bottom named Satan who isisn't his pawn and will torture you forever (which isisn't Jesus' doing) unless you take proactive steps all your life to advance the DEI of which Jesus spoke (the egalitarianism).  

Where thoughts actually come from is the same place from which souls come.  When people say, basically, "I welcome being robbed/raped," that is not them--that is from their body getting this urge to cycle the environment in which they live.  That is why they do such things; feel that way.  You can show them an anecdote, 10 anecdotes, 100 anecdotes, whatever, that migrants will cost them money and never become like duplicable thems who have good jobs and respect individual property, but it's not going to work.  Like buying a megaphone and lecturing the sky about why rain should not fall today, it is not gonna happen.  Those people feel overpoweringly driven to cause that society to end, and if they rationalize why to themselves, proving that the why is bad will never work.  White women will want to not have children and not form reproductive unions, guys will commit suicide or think it is good that the evil White race should end, and trying to stop it is like frowning hard at a dumbbell and trying to tell it not to be heavy (or like think-texting what you did that day to an invisible man in the sky who loves you--throw in some gratitude to said invisible sky-man and you've got yourself a prayer).  

You can be OK with this, right?  No, maybe you can't, but if you read for fun, you and are probably vulnerable to this.  In the same way that oak seeds at the right time are "vulnerable" to growing into an oak tree when dropped into wet soil with nothing else around, Decay are going to cause decay and many others will be along by them led.  Their behavior will seem nonsensical to some, but it actually makes a lot of sense: they are trying to make their environment decay, even though they generally don't think so.