Juzang knew full well, just like every other recruit Cal has signed, that Cal was going to be recruiting the best players he could sign every year. As Cal has publicly stated many times, "This ain't communism, the best players get to play." and "Kentucky ain't for everybody" Juzang couldn't beat out Quickley or Maxey for playing time his freshman year. He had no reason to believe Cal was not going to bring in top tier guards in the next recruiting cycle, especially since he knew Maxey was leaving. Boston and Clarke, both at 6ft. 7in could have also played in a three guard line up which Cal has played many times.
I understand kids want to play and they don't want to sit on the bench with limited playing time, "waiting their turn" when that "turn" may never arise because they can't beat out their competition. No player has a right to have an expectation that their coach is going to preserve their future playing time by not recruiting the best players he can sign. Beating out your competition is the nature of the beast when it comes to team sports.
Juzang left and he has had success. I'm happing for him but I certainly don't blame Cal for him leaving. Cal, by all accounts, including his own, wanted him to stay.