I don't get why Larry Scott has to or wants to wait on the SEC if he wants to expand. So much of this stuff that people report as fact is just rough ridin' stupid nonsense.
It's because while he wants to expand, a portion of his bosses (4-6 UPs) don't want to unless they have to. The only way he can leverage those UPs into giving him the authority to expand is if they believe they have to in order to keep up with other conferences. Larry Scott would love to go pick up OU and OSU right now, he just doesn't have enough support from those that give him the authority to do so.
why do they need to "keep up" with other conferences?
That I don't understand. My take is just that Scott wants to grow, some UPs do not, and that Scott has convinced them that they need to "keep up". That's the angle he is taking with them. Maybe it's a risk/reward thing. Once they feel that superconferences are inevitable (someone else move towards it first), then they must start taking risks to make sure that their supply of new teams doesn't run out. They may feel that the if the SEC goes to 16, they might go after OU, so they better lock up OU before the SEC can.