Why leave? Money. He makes 600k. Miami said it can pay 1 million. Thats 400 thousand reasons to leave. Also, he doesn't call plays at Oklahoma. He really wants to be a playcalling OC. Third, Lincoln Riley is going to NFL. No telling if next coach will have same philosophy.
The fact that he hasnt called plays shouldnt be a showstopper. Thats overrated. Our current playcaller has decades of experience, coached Heisman winners, and won a national championship as an OC. Hows that working out? Far more important is the offensive scheme. Scheme matters a lot more than being able to read plays off a sheet. Bedenbaugh is an Air Raid guru and worked with Riley to design the Oklahoma offense from scratch, which ended up blending the Air Raid with a power run game. That scheme would obliterate the ACC. Pair that South Beach Spread offense with Diaz's defense and you got yourself a stew.