Is anyone really whining that blink182 wrote their untitled album? Not one immature joke in the whole album. But people accepted it and understood their growth. I guess BFS has just made a name for themselves as a funny band, with funny songs. You don' think they could ever evolve beyond that?
They've written some songs focusing on serious topics along the way, from "Pictures He Drew" to "99 Biker Friends" etc. I'm not going to go through their whole discography but I'd say at least 1-2 songs on each album has a serious angle to it.
Blink-182 evolved, yes. But I'd venture a guess that most kids aren't going to see them for songs off of the self-titled album. They're going for Dude Ranch, Enema, and TOYPAJ songs primarily.
If you wanted to bring up a band that evolved where kids aren't whining, I'd point out Green Day. They went from masturbation and hookers to politics and social issues, and it led to a smash hit of an album.