but he often came off as pretentious and very confrontational and rude

This is about as accurate as it gets. He was intelligent, there's no doubt about that, but the problem was he believed himself to be more intelligent than he actually was. He literally was a know-it-all with an answer, solution and fix for everything.

The problem with intelligent people who are extremely arrogant is that they are among the most stubborn people there are. When something is inherently subjective, they don't see it like that. To them it's only objective because their opinion can't possibly be wrong. They won't concede a millimeter in a debate.

I've dealt with people like him before so his shtick was nothing new to me. I thought the guy was absolutely insufferable. For many others, he was a novelty when he first hit the scene, his articulate and well thought-out comments were refreshing. But the honeymoon doesn't last long. The more he types out, the more he shows his true arrogant and pretentious self. This is what essentially happened. People finally recognized and saw his ego for what it was, and they had enough.