Sure, everyone has the right to share their opinion, but if you dislike something so much that you can't find a single positive thing to say, it's better to simply not return to that project (after leaving construcitve criticism of course). Instead of playing it repeatedly just to find more things you don't like.
Also, sharing your opinion doesn't mean I have to agree with it. If you don't consider the possibility that your opinion could be wrong, the discussion won't go anywhere.
Lastly, it's important to distinguish between sharing an opinion and just repeatedly criticizing and hating, which doesn't help at all.