And yet Joe has heard of Whitesnake and Def Leppard, both of whom are way older. But that's not the point. FNM have been out of the spotlight for a long time, so if you talk to a bunch of 18-24s they aren't really going to have a very informed opinion.
FNM ARE a great band and DEFINITELY deserve billing above Whitesnake, and their reunion is a HUGE event. Joe should be more open minded and just go listen to them, and if he doesn't want to? It's a festival, I'm sure there'll be something more to his taste on a short walk away.