Personally I think Kaczynski was influenced more by his inability to get a date in his entire life.
You should read his manifesto, the dude had some funky ideas about society and there's no excuse for murdering innocent poeple, but he does defend what he believes in very vigorously. He wasn't a man without an ideological backing.
"One of the most widespread manifestations of the craziness of our world is leftism [...] When we speak of leftists in this article we have in mind mainly socialists, collectivists, “politically correct” types, feminists, gay and disability activists, animal rights activists and the like [...] Thus, what we mean by “leftism” will emerge more clearly in the course of our discussion of leftist psychology. (Also, see paragraphs 227-230.)
[...] By “feelings of inferiority” we mean not only inferiority feelings in the strict sense but a whole spectrum of related traits; low self-esteem, feelings of powerlessness, depressive tendencies, defeatism, guilt, self- hatred, etc. We argue that modern leftists tend to have some such feelings (possibly more or less repressed) and that these feelings are decisive in determining the direction of modern leftism."
You can get stuff of this quality by the shovelful from your typical bad subreddit, although usually not by one person all at once.
So he made a (controversial) argument about leftists which actually fits in with his broader point that humans these days are not able to self actualize and therefore suffer from repressed feelings. IMO the statement he made is significantly less crazy than Freud's "scientific" theory of penis envy (https://en.wikipedia.org/wiki/Penis_envy#Freud.27s_theory), which was treated as an actual theory by the scientific community for _decades_.
It's a bit polemic about leftists in that regard, but do you think the overall point is invalid? If so, maybe argue why instead of just calling him crazy.
The Communist Manifesto
Thomas Paine's Common Sense
Jonathan Swift's A Modest Proposal
Each of these is shorter than 35k words. In fact, they're shorter than 35k words taken together.
See, this is the part of the dialog where if you simply point out which premises are "nuts" and then argue simply and objectively about them, then actual conversation happens (or is finished!).
Trying to shut down the whole thing down with the vague term "crazy" (something so obviously self-evident to be in need of no justification) is really a disservice to everyone.
I am not sure what point you are making with those other works. The Art of Computer Programming is three (3!) volumes. Is Don Knuth a nut? Euclid's Elements is also huge. Nuts?
Have you actually read the manifesto and tried to understand it instead of just dismissing it as "crazy"? The only way to distinguish nonsense from sense is to...try to make sense of it.
IMO the only crazy part of the manifesto is the explanation and defense of his violence. But given that that violence almost certainly _did_ lead to a wider proliferation of his manifesto and ideas, it's even hard to argue that that was not an entirely rational (if inhuman) strategy.
Now, Elliot Rodgers had a funky manifesto.
It might be surprising, but women in fact don't have civilising effect on brutes nor cure mental disease nor change peoples with philosophies (which he possibly did not had). Plenty of violent people with girlfriend in history.