What most have noted is that his decision didn't make financial sense, which is probably true.

Mika comes from a private equity family; money is not going to drive this kid. He knows he is going to have money to matter what happens in his basketball career.

I think he wants to have fun, and he simply wasn't having much fun at BYU. Plain and simple. It seems to me the 2017 cougars are more of a team and having more fun on the court vs the prior 2 years, but he probably didn't anticipate that. He probably felt like he was playing in 2 feet of tar; at least that is what the last two years felt like as a fan.