They didn't have to lower their standards a whole lot to fit in. Don't get me wrong, I don't think Mizzou is anything special as far a corruption surrounding the athletic program goes. Let's just say there is a healthy culture of corruption there going back at least four decades. Pretty common stuff. The boosters have had a nice hand in providing perks to athletes, and cutting corners to make sure athletes stay eligible isn't anything new. I wouldn't accuse long time coach Norm Stewart of being especially corrupt. On the other hand I wouldn't accuse him of running anything approaching a clean program either. There's a good reason that Quin Snyder hasn't been involved in collegiate coaching since he left Mizzou. I'm not sure to what degree Snyder actually created that culture but it ran amok during his coaching term. The school did get away super easy. I don't think the NCAA could get anything real solid on them that time around.
I haven't kept track the last dozen years. I really don't talk about Mizzou much anymore with my old friends that went to school there. From the looks of things, it doesn't look like the culture has changed much.