I think Bob really, truly, literally doesn't understand that movies aren't real. I mean, he'll say "I studied new media, friendo, of course I know movies aren't real", but on a subconscious level he doesn't realize that it's not just the characters and the stories that are fictional, but also the internal rules of the universe. He truly thinks that the nerds always win over the jocks and bullies in the end, and that by virtue of being the underdog he would grow up to come out on top, because the John-Hughes-end-montage said so. That this didn't happen broke his mind, quite literally. He can't resolve the cognitive dissonance from that, so he's spiraling further and further out of control. The bullies won, and he can't understand why. To him, this should be fundamentally impossible, and time is running out. He's pushing 40 and he knows he's absolutely pathetic. He wanted to be James Gunn, or at least Kevin Smith. Instead, he became the obese version of Napoleon Dynamite's uncle.
/edit:
His case would be quite sad. There's obviously something fundamentally wrong with him, but there's not really any way he would get help. He's functional enough to be left alone. With just a bit more understanding on what reality is he could have ended up like his brother: With a house and a wife and kid that he dearly loves. Sure, they're basic white trash, borderline hoarders and messies, but Chris is HAPPY to a degree that Bob is incapable of feeling. He absolutely made it compared to his brother. He should leave social media alone and focus on his family and not get roped in to Bob's increasingly unhinged political spergouts. I get that Bob is also his family and that he loves his brother, but he should just stay away from the politics. He basically doxed himself by accident and, due to his proximity to Bob, is already examined by this place.
/edit2: I forgot where I was going. Bob's case would be sad, if he wasn't so goddamn malicious. But then he wouldn't be Lolcow and nobody would care.