One of the really weird things about Bob is that most lefties, even the SJW types, seem to feel the need to at least have a veneer of respect for the lower classes; to at least pretend to have a sense of compassion. And to stop being a snarling right wing troglodyte for a moment, I honestly believe lots of folks on the left genuinely have compassion and empathy for the poor, the disenfranchised, and the less fortunate. Bob has none of that. He's totally comfortable writing off vast swathes of the populace as dross to be ignored at best and actively crushed at worst. Lately he's been trying to characterize this sort of stuff as "gallows humor" but I don't think anybody's fooled -- there's too much nastiness and bile in his original posts.
I'd blame it on :autism:, but I don't think that applies to Bob -- one of the enraging things about him is that he's got a level of slyness and self-preservation a lot of lolcows don't have. Think of his keeping his mouth shut over Devin Faraci, for instance. Maybe he's just so deep in the bubble he has no idea how vile his opinions tend to be.