As a regular on the Wonder Woman board, I can definitely sympathise (Gaelforce had to update the forum rules, it was so bad). That's why at least I try to be clear in articulating why and how I don't like something, point out the things that I think work or find good, and avoid sweeping statements. And try to limit my posts with negative judgments to as few as possible.
I like to think I manage at least some success in that. But even well-behaved expressions of negative opinions can become overwhelming if there is a flood of them from different people.