I don't know about anyone else, but I say what I want to say, what I think, and what I think is a good answer to a question - and that's it. I don't really think HubPages staff cares what I, or anyone else, says (as long as it doesn't violate TOS).
If you mean questions such as (for example) health-related questions (when people often tell the asker to seek information from a health-care professional), one reason people give that kind of answer it that they know/believe it is the right way to answer. Also, people are often not going to answer SOME kinds of questions because they're not sure the asker really needs the answer for himself (or whether he's posted a question to get an answer that he can go post on some other site, and maybe earn some money by posting the best answer). The fact is people SHOULD be getting their medical info from somewhere other than HubPages "Answers", and the fact is there ARE people who ask some types of questions for reasons other than needing a solid answer for the reason they imply they do.
On the other hand, if you mean questions about HubPages and how to earn, get traffic, etc. (or else whether people like the site, don't like it, etc.), I think most people are pretty free to say what they want, and what they think is a good answer to someone looking from feedback from other Hubbers.
When it comes to the Answers section on here, the only things answerers may get out of answering are a) maybe thinking they helped someone who legitimately needs help, b) having what they think will be a good answer under their own "Hubtivity" on their profile, and/or c) killing a little free time by challenging oneself in coming up with a good answer (either a solid one, a funny one. whatever mood the answerer is in at the time). Answerers may also get an idea for a Hub, which is a whole other thing.