All 'opinions' are 'answers', but actually not all 'answers' are 'opinions'. I think the 'opinion' label is therefore inaccurate. If someone were to ask "What is 1 + 1?", it wouldn't be merely my 'opinion' that the answer is '2'.
Not everything is an opinion, but everything IS an answer. Correct, incorrect, honest, a lie, smart, or stupid... It is an answer non the less. But there are some questions that you can give an answer to, but not an opinion. Questions that ask for facts. So it's silly to use the word "opinion" instead of "answer" on this site.
In a way, I think Opinions suits this site more, because more often than not, the questions are something which can only be answered by an opinion and as such when they are called "opinions" from the start it's evidently clear that the answers can be highly subjective.
But if a question asks about something which can be answered with facts or the answers can be supported by facts, them being called "opinions" can be give the false impression that the facts presented are not facts at all, but rather individual speculation and the like.
All and all, I'm indifferent, but if I had to choose, I'd take the "Answers" over the "Opinions".