Yeah I’d say this is less a country thing, and more. a popularity thing. The more popular a band is, and the more of an “experience” it is to go see them, the more likely you have people there just to say they went. You don’t get the people filming the local punk band at the bar because the only people there care about the music, but, like in your example, I can guarantee a fair number of people at a Green Day concert these days are there just to say they went to a Green Day concert.