There's stuff you and I have probably never heard of. When my wife and I were in Chicago earlier this year we passed Soldier Field on our way in to town and it was jam packed for some sort of Asian boy band. There's all sorts of weird stuff out there that 80,000 teenagers will go see. For that matter, there's all sorts of weird stuff that 80,000 nostalgic baby boomers will go see so that they can pretend they're still freewheeling hippies and not corporatist leeches. I'm sure they can drag the corpses of Mick Jagger and Robert Plant up there once a year.
On topic, the NFL isn't going back to St. Louis. They are trying to do damage control after the lawsuit St. Louis brought against them was allowed to go to trial (the NFL was trying to keep it in arbitration). The trial is going to be horrible publicity for the league and this is them trying to get in front of it.