I think a lot of it has to do with how much presense you have in the community. If you make a lot of comments in other people's work they will likely make comments in yours. Simply put they'll remember you and notice your work out of the 3 million images that get posted every 20 minutes. More than likely this also works for people who gab a lot in the forums. They're remembered and they're seen as social so they get comments. There is some issue of quality to it. But to be honest some of the most commented pics are not in the higher ends of quality. We've all seen a pic go up and get a pile of positive comments within minutes but notice that the image is not only not that good but subpar for the artist's norm. There's also a bit of a work that quietly disapears even though it may contain something very powerful and well done. While quality does play a factor. I suspect being nice in the sandbox or at least being well known plays a larger one.

Truth has no value without backing by unfounded belief.
Renderosity Gallery