Quara has its bias, but it's not really worse than any other discussion platform. I think the quality has declined. They have a campaign going where they pay people to ask questions, but seemingly they don't offer payments for answering questions. This has lead to an influx of redundant and insincere questions.

So if you write an answer, you might be answering someone who's just writing as many questions as possible to make a profit. Also, you're answer may be collapsed. If you want to see collapsed answers you can view most of them (they are sometimes outright deleted, I would guess if doxing was involved or something of that nature). From what I've seen, some of the collapsed answers are of similar quality to some of the more popular answers. So don't expect much discussion or debate over unpopular opinions.

So if you're wandering if there are reasons why you may not want to contribute, there are some things that would give a reasonable person pause. As far as asking questions and getting feedback; if they don't like your question it may be taken down. For noncontroversial questions it seems like a decent platform. Just take everything you're told with the same grain of salt you would give anything else you see on the internet.