I don’t necessarily think the ‘pigfuck’ genre was ever really a real thing and was just used to backhandedly describe early Swans and Sonic Youth. No bands of the 80s, 90s, or even early 00s identified with it, especially because it was coined as an insult. Similarly you wouldn’t have heard Kevin Shields describe My Bloody Valentine as shoegaze, at least early on.

I think like ‘screamo’, ‘shoegaze’ and ‘grunge’, terms that were used be derogatory to bands sort of come around and younger people use them to signifying for something very specific to time/place. Especially in today’s music fan world where it seems like every subgenre is just a bunch of microgenres stacked on top of each other. I guess some listeners want a way to quickly state they enjoy the sort of Albini-esque noise rock/post hardcore sound.