It's fun, it gets you lots of upvotes because maybe it makes someone smile. But it's too damn easy. It short-circuits real discussion with pop culture references and snarkiness. Conversation is quickly suffocated when solid posts are blanketed with 4chan memes as responses.
It comes down again to the quality of the comment. Is it a good humorous comment (e.g., not cliched, satiric, perhaps humorous and insightful, and so on), or is it a bad humorous comment (e.g., stale, not actually funny)? Right back where we started.
As Homer Simpson says, "When will people learn? Democracy just doesn't work."
That, in turn, is due to people caring more about rhetoric than reason. Regardless of whether something makes sense, if people can say it in a way that conveys the right image, they are "right."
And this is all because we spend way too much time passively consuming media, and are consequently taught to process things via image vs content.