In reality it is a matter of investment more than it is weather or style of play or anything else. Not saying weather has no effect, just that the investment levels is a much bigger factor.
The SEC has passed the PAC12 simply because they decided to put a whole lot of money into facilities/broadcast/recruiting/etc... We are starting to see the ACC do the same thing - adding in teams from Duke and Clemson with new facilities is going to be huge over time and also I am hearing there is pressure on UofMiami as well to add a team especially since they have invested so heavily in baseball over the years. The PAC 12 has more talent locally, but they need to be real wary that they don't start to lag way behind. There is no excuse that explains why the PAC 12 is not broadcasting at least 4-6 games every weekend.
Big10 is lagging behind. If they WANT to invest, they could. Right now as a conference they don't appear to want to.
I will say that Purdue's new $13M softball facility is Mac Daddy!