Foo Fighters seems like a boring band for a pin. Their music is fine but it's certainly not exciting or anything I'd think to build an interesting theme around. I'd be really surprised if there were a lot of people in the pinball demographic that were super excited over Foo Fighters.
I can't be the only one completely tired of the endless nostalgia mining every company is doing these days? BTTF is not any where near as saturated as marvel/super hero stuff is these days but it feels like something a company who wants to desperately avoid risk would do. Pay for the license and you know you get a certain amount of people to buy it regardless of how good the product is.
What about a sports theme? It seems like a long time since we've had one of those and those were some of the more fun older pins.