It's at a peak right now because the tendency of absolute loons to hound someone who wrote a thing they don't like across every platform that exists is also at a peak, so scrubbing your trail when you move on in hopes that it keeps the crazies away has become a more popular tactic.

See also: scrubbing your trail when you have life changes (eg. new, sensitive job) that might turn the possibility of said loons dragging your fan activity into your real life more than just an embarrassment, because this is a thing that has actually happened in some fandoms, because some fans are fucking bonkers.

Fan behaviour patterns will shift again, and so will the tendency for fans to go scorched earth on their old work. For now, just save anything you think you'll definitely want to go back and read.