Why do you think Gabriel moved out?

Gabriel's mind was affected by a war injury. He hd a metal plate in his head and was never quite right. We learn from Rose that Gabriel left because he wanted a place of his own.... Gabriel says he moved to keep out of the way. In my opinion, Troy's attitude made have helped a bit, not to mention, Rose feels he needs to be hospitialized, though I see no evidence that she tried to make it happen.