Brian Goff at The Sports Economist argues that it is the 1984 SCOTUS decision to break up the NCAA cartel in TV broadcasts that has led to conference "realignment mania."
Of course, a major element of these reformulations are the dynamics of joint ventures such as conferences. Typically, joint ventures, especially cartelized ventures of competitors, are more stable with greater similarity among members. Big differences in revenues or cost structures creates frictions — the typical big-market, small-market issues regarding revenue sharing and so on. The TV restrictions restrained the frictions. Without the restrictions, the big-time revenue producers tend to gravitate toward each other. The same influences exist in pro sports but there aren’t any viable alternative leagues to join, so the bigs and smalls coexist.
This makes a lot of sense. But I find it interesting that the issues in the Big XII stem from Nebraska and aTm having issues with Texas. Texas serves the biggest market in the Big XII and they want to serve that market with their own network. Perhaps it's simply that the variance in market sizes in the Big XII is just to dadgummed big and this shakeout, if it indeed happens, was going to happen at some point anyways.