It has! I've been in a teen show fandom where R-rated fics are the norm for the past 3 years, so I thought it was just that fandom, but now that I'm getting into other fandoms again, the more I realize it's happening everywhere. I've even started to almost unconsciously tone down my own fic for fear that people will think really explicit stuff is creepy.

There was a discussion about AO3's "underaged" tag on fandomsecrets the other day. A lot of people are dissatisfied with it because it doesn't let you distinguish between what HP fandom used to call "chan" (no one uses that word anymore apparently) and fics with older teens (16-17), which don't seem to bother most people (I personally don't use the archive warnings for older teen characters, but tag in the optional tags or mention their ages in the summary/character note). There seemed to be a general consensus that fic with kids is gross and no one is going to be writing that kind of thing anyway and no one really argued the opposite and there were no accusations of kink shaming. It's sort of ironic that LJ started to die out because of Strikethrough and censoring chan, but now it hardly exists anywhere.