There is no defending this. Trying to do so simply means you're going to defend anything and everything regarding Cal and the "one-and-done" system, no matter what. And that's coming from someone who defends Cal virtually every time, but not this time.
To be clear, I have absolutely nothing against the system and think it has been great for UK. But this particular situation is a joke. I always remember Cal saying something along the lines of "if we do right by them and help them reach their dreams, they'll do right by us and help pull us to where we want to go." I think the vast majority of fans are on board for that.
But when it starts being an entirely one-sided deal, there's nothing wrong about calling it exactly that -- and being disappointed, or even angry about it. That doesn't make you a hater, or selfish, or anything remotely close to that. It simply means you can look at a situation objectively and know when you as a fan are being asked to swallow something that is unjustifiable.