Seriously, I see what's happening on HN and Reddit, but don't lionize Ted Kaczynski.
First, saying "I agree with his ideas, not his methods" is akin to saying "sure, but Anders Breivik had some interesting points about political correctness run amok". Kaczynski's and Breivik's ideas prompted them to kill people. It wasn't just a coincidence; it was the whole point. The foregone conclusion of their ideology was that it "had to be done".
Second, Kaczynski's manifesto is a rehash of the same tired anti-progress ideas that have been cropping up since antiquity. A longing for some made-up bygone era when men lived meaningful lives in harmony with nature, juxtaposed with the purported moral, societal, and environmental decay of today. You can find complaints of this sort in ancient Greece, in the Middle Ages, in the 18th century. By all metrics, our lives keep getting better: less poverty, famine, disease, war. Yet, we keep imagining how idyllic it would have been to be a peasant in the 13th century and die of dysentery or because your turnip crop failed. I bet you could find meaning in that.
Misplaced nostalgia aside, the other problem with most of these ideologies is that they involve force: in common with some other terrible revolutionary movements, they posit that the minds of the "sheeple" are too corrupted to see the truth. Whether the remedy is blowing things up or hanging a lot of people is just an implementation detail.