The thing is overall the Big 10 is pretty good. They have a lot of teams that a better than average like Illinois, NW, Purdue and Minn. I'm not saying they are great teams, but they have much better resumes then OU, OSU, and ATM. So when those teams beat up on each other, the get quality wins out of them.
For example, Minnesota's conference wins are over Indiana (RPI=16) , Penn St (137), NW (36), Ill (42), & Neb (111). So they have 1 really good win and two solid wins. Sound familiar? We have KU (5) and then K-State (48) and Texas (53). Now I think we all would agree that we are better than Minn, but our resumes are similar. The difference is their wins over mid to lower level Big 10 teams looks better than our wins over mid to lower level Big 12 teams.