Because he's Thork. He has his little way of infuriating people in a big way. Though I think he's smart and generally logical, even I have my issues with him. I don't know if he means to, but he phrases things in a way and says things that almost seem to be begging for someone to get upset about it. Maybe he was just inherently part troll from birth?
Plus his ego. That's a big one for me. I don't like big egos.
This isn't meant to be a Thork-bashing post, I don't dislike him, just answering your question.