You should read his "Manifesto." Kaczynski was a highly intelligent but asocial wretch who couldn't get laid, so he used his intellect to create an elaborately argued worldview to cast the blame for his misery, not on himself, but society at large. That worldview was so convincing that he not only fooled himself, but many other intelligent people who really, really, ought to know better.
Incidentally, as an aside, I have personally had the honor of being called a "kook" by the Unabomber, in one of his many correspondences.
If you read that manifesto, he made a lot of fine points. But you shouldn’t murder innocent people with letter bombs.
He called you a kook? Do you have the letter? Seems like that would be a collector’s item worth framing! LOL.