The problem is it's being normalized. When ****** had his brownshirts there was lots of window-smashing and no lone shooters, and it wasn't because brownshirts were just angsty teens with blue hair who listened to punk and wanted a group to break windows with.
If I go to a college class and say something like "Shakespeare is great" someone will say I'm oppressing them and I should join them in replacing Shakespeare with some whiny radical feminist author who no one's ever heard of because their writing simply isn't very good. Having a common culture of some form matters a lot because without it we'll go to the Stone Age. People don't have to love Shakespeare and opera but replacing it with authors who aren't very good isn't a viable alternative.