This. It seems that most often the top comment is a direct rebuttal to whatever the original post was. While there is nothing wrong with this, and it's actually healthy to have opposing points of view, it seems like the community as a whole has gotten into a rut of criticizing everything. There are other ways to have constructive discussions than always pointing out what's wrong.
There was a study somewhere stating that those criticizing are perceived as being smarter. I guess we know that instinctively. And I think this applies to self view to: when criticizing someone's else point we appear smarter to ourselves.
There's too much bubble talk lately and people's projects are still half-baked and aren't ready for the bubble to pop, so they're trying to slow it down by cutting each other down. Crab mentality.