Penn St, in my opinion, is misplaced, conference-wise. They joined, I believe it was 1993, partly because the Big Ten was an established conference, and allowed them the equivalent of a BCS 'bid', if they were the conference representative. To my knowledge, Penn St. has been in the BCS exactly 3 times since their Big Ten 'inaugural' season. They've been in the Rose Bowl once. And that says a lot about how deep the Big Ten is, competitively-speaking. As an independent, Penn State fared much better, in general. What the Big East is, in effect, is a conglomorate of traditionally 'independent' teams, and that suits Penn State's history much better, and they likely would do better in that environment. I'm at a bit of a loss to understand why they remain 'true' to the Big Ten, but they are, and that's commendable.
Penn St. is in the B-10 because they fit geographically, economically, and they have the same mission educationally(is that a word?
) as the other member schools. They are also a very big school and that fits with the big ten. Big Ten schools share grant money and share research projects. These schools get alot of money because they are joined that has nothing to do with athletics.
Missouri comes closest to a fit because they have excellent reaseach facilities. Iowa St. doesn't fit in the B-10 at all.
I am not denegrating Indiana and Northwesten. They both bring a wealth of things to the table in the B-10, just not in football. Both schools have a pathetic record in the B-10 in football. That isn't a shot at either school that is a fact, bore out by their histories.
Penn State would have done better in football had they remained independent. That is part of my argument of why Notre Dame should be in a conference. Conference play is tough, because all the teams know each other very well and the conference games carry more weight then non-conference games so the teams are playing with something on the line.
The Big 12 may not need 14 teams, but the B-10 doesn't need 12. They don't want 12 teams. If they did add a team it wouldn't be Iowa State and probably wouldn't be Mizzu.
Notre Dame isn't going to join the B-East in football. They aren't going to join any other conference in football either. They have no reason to join a conference. Until they have financial pressure they will never, ever join a conference because they have the best of all worlds.