A. If he isn't ready, it could really stunt his growth.
B. Service time. Why burn control now in meaningless games they are going to lose anyways, when you can trade that for when the team should be good ?
I agree, the team sucks, and outside of watching Moncada, and Abreu bat, and Lopez pitch, it's already becoming very hard to watch. But patience now is key. They picked a lane. Changing now and calling guys up prematurely would almost certainly blow up in their face. We all just have to take it now, and hope it pays off next season or the season after.