I think you are looking at a combination of all four happening in fairly short order, causing the shift.

One other factor that should be discussed is that the BIG made wrestling a priority when it invited new schools. Yes, football and cable subscriptions were the driving forces to bring in Nebraska, Rutgers and Maryland. But the BIG expanded in a very methodical way and seemed to place a special priority on making sure that all new members had solid wrestling programs. It is almost as if somebody noticed an under appreciated niche market that could be exploited. Since expansion, attendance is up considerably at several schools - note RU's jump in numbers. This has turned the B10 into THE wrestling conference. It dominates the sport the way the SEC has been dominating football. This has turned the Midlands into a mid-season preview of the NCAA tournament.