Capel's problem was two-fold.
First, he didn't want to be the kind of coach that Sampson was, and LK currently is. He didn't want to take 3* talent, mix in the occasional stud, and win because of coaching. He wanted to win the same way Drew has been winning at Baylor. He wanted to land a bunch of studs, and he wanted to sit back and watch them ball. Like he was used to at Duke.
Secondly, he didn't want to work up to that. He didn't want to put the time in to stabilize the roster after he lost 3/5 of that first class. So he went big. He went after the best. And for the most part, he struck out. He was able to land a couple of kids that had giant worts. Kids that a lot of the top programs didn't recruit very hard, or that were plan B and plan C type kids for them. But he didn't have anything to put around them. And he didn't have a leader to keep them in line. He rushed the process, and in turn, had rosters full of players that just didn't fit, and didn't have enough overall talent to win with his crappy coaching. Had he built things back up a bit, then went after the occasional monster recruit, without sacrificing so much, he might have done better.
Hind sight being what it is, Capel just wasn't a good fit at OU. At all. OU is probably going to need coaches that are a little more grounded than Capel, and a little more blue-collar.