Looking at this from Alex's perspective..
He just had a junior year where his minutes were dramatically cut back and his production dropped. He didn't get along with his coach and he has pressure from his family, most notably his loose cannon of a father. He has one year left to prove to the NBA that he has value and UConn is currently banned from postseason participation next year. He has the chance to pick his spot and make a one-year run towards a career as a professional basketball player.
Leaving out the emotion brought on by his dad's intemperate comments, transferring is not unreasonable nor would I define it as quitting.
The kids get one go-round - if he thinks that his best path is to go elsewhere, he has to do that. He doesn't owe us anything - 99% of us will forget he exists a year after he leaves.