I think it's a symptom of the new pop culture (millennial?) trend of feeling like you should be protected from having to feel anything uncomfortable. It's the same phenomenon that threatens to undo our freedom of speech when all the voters are millennials and post-millennials. I mean maybe there are some people who legitimately need trigger warnings, but I think those people would be exceedingly rare and I think the timing of the uprising of trigger warnings is no coincidence. TBH though I don't even remember seeing a single trigger warning out in the wild. All I ever see is the controversy surrounding this alleged phenomenon.