You're trying to associate two things that have no correlation. That's where you're failing. This trend in adolescent activity doesn't have anything to do with football game attendance. If what you assumed was true, then game attendance from young fans would steadily drop. It hasn't and it won't. College kids will flock to games no matter the time of year, even those outdoor bowl games...because you know there are a hundred bowl games. Those points you're trying to counter with are silly.
And all you have to do is read some posts here when the dome topic pops up. People say "I used to love going to the games when I was younger, but now I'd rather watch on my big screen TV and not be sitting in the cold."
Going to the game is a social experience that younger people are going to gravitate towards and eventually grow out of as they get older. Die hard fans will always go, but demand a more dome-like experience as time goes on.