To me it seems like this is an enternal struggle of /having to be/ a "hipster", and move to the newest services/forums. In the sense that the only untainted grounds will be the ones where there's not that many people yet, or people joining/promoted to influencial positions are scrutinized.

It takes very few bad actors to poison the well. At least on Reddit, there's a myriad of small subreddits which makes it more difficult to infiltrate all of them effectively.