The mean is attracted to quality, but doesn't 'get it', and drags it down. So you end up with regression to the mean. It happens to everything 'cool' everywhere, all the time.

When a community is young and niche, it only attracts those who seek it. These seekers get it, but they have that 'je ne sais quois' that is often envied by people whose motives have no resemblance to the theirs. Once the second wave hits, it is downhill from there.

tldr hipsterism.