Basically, it's a reaction to people on social media calling anybody showing any amount of enjoyment from something "cringe."
Cringe is dead, let people enjoy things, embrace the cringe, etc.
I think I've seen it largely in Millennials who have reached a point where they just don't care what the current trend is or what people think of them. They're at the point where they're just like, "I'm in my 30s/40s, fuck it. I'm gonna blast Linkin Park and My Chemical Romance like it's the early 2000s and enjoy the things I like because I can't be bothered to care what people think."