It's pretty common for right wing nerds to use the unibomber manifesto as their one single, token piece of "leftist" theory they've engaged with so they can pull the old "unlike you I can read books I disagree with "

I think it's mostly because 1) it's edgy 2) no real leftist movement developed from or even has been attached to it, so it's harmless to them and 3) he spends quite a lot of it ranting about feminists from what I remember