Yes, it’s because a lot of kids started wearing their dads’ classic rock and grunge metal band shirts, so much so that it became fashionable, and stores like Target and Walmart sell these shirts again.

Then you have the kids who actually listen to those bands and think very highly of their learned musical opinions (reminiscent of “le wrong generation” kids).

There’s now both a stereotype for the type of trendy person who wears a shirt for a band they’ve never even heard of and the type of person who judges them as posers.