From what i understand, most of them are rambling diatribes of mania, depression, bitterness, and loss. Often with some racism and doomsday cult thinking thrown in.
Kaczynski’s manifesto being a notable exception.
Discussion
Looking for this one:
Nvm I just found it. Looks like he had some issues with religion. He defines people as good and evil and puts good and evil on a uniform distribution which is just wrong imho