Hm, 'indifferent' might be too negative an attribute. What I basically mean is that Chase isn't opinionated for the sake of being opinionated. If he can't think of a solution himself, he goes along with House's, because that makes most sense. I think Chase doesn't like to waste his energy fighting lost battles. His interaction with his father in Cursed shows that Chase does argue with authority figures if he thinks he's right. However, it also shows that his father likes to dismiss Chase's opinion and is a superior bastard, at that. So maybe Chase has learned that it's futile to waste words to convince someone who obviously doesn't want to be convinced - especially since, as you say, has to see and act quickly in order to save patients' lives.