Moy, do you disagree with the notion that it's now much harder to take a low/mid team and make it a big-time program?
All worlds have random examples of teams making runs here or there, but let's be honest about the effect as a whole.
(And even the examples that you hand-picked aren't that compelling to me ... Butler hasn't been past the 2nd round of the NT in a dozen seasons; Mizzou-KC literally beat no one all season and then beat only one BCS team -- a 10-loss LSU squad by a point -- in the NT.)
I've yet to see anything that comes close to dispelling the notion that the rich have gotten richer. Check out Allen, which used to be an absolute bastion of low-mid teams excelling (Montana, Southern, UWGB, Cleveland State, Yale, Boston U, Idaho State, etc). Now, the top 19 rpi teams are from BCS conferences. Last season, all but one of the S16 teams were BCS ... with the lone exception coming from a sub-regional where all four schools were non-BCS.
The game done changed, my friend.