He has a lot of what I call 'bait' comments, trying to get people to respond in a way that allows him to tear them down. He already knows how he's going to answer the next step in the conversation, having prepared the material long ago. Though it's not quite copy/paste, it's close, kind of like a telemarketing script. I hardly see anything constructive, and find myself often downvoting him due to repetitive baiting with no end in sight.

Look at his actual comments

There's no question that many of his comments aren't helpful. And he does talk about issues that are outside his expertise and doesn't listen to people telling him otherwise (one of the more egregious examples would be in the comments to this post), and Tim responds negatively to people telling him that he is not informed about topics. But Tim does make helpful remarks. Examples of recent unambiguously productive remarks include this one, and this one. I don't see enough here to conclude that Tim is in general a problem.