When a player commits to UCONN, she doesn't do it JUST to be part of a NC team; she does it because she BELIEVES she can compete against the best players there are in the best program there is, and that belief is validated by the fact that UCONN recruited her. A player wants to play; what is the point of winning 4 NCs in your college career where you only get to play garbage minutes? What kind of achievement and satisfaction an athlete would have in that?
At some point you realize, perhaps to your own disappointment, that your abilities fall a bit short of the level needed to earn quality playing time at UCONN, but still more than enough to shine elsewhere (though not likely to win NCs), you decide to transfer. To me it is the most rational thing to do, and Ekmark is a prime example of this (Butler's situation was similar but not identical to Ekmark's; I don't believe Butler would have transferred without the arrival of Z).
I have read a lot of posters on this board claiming that winning NCs is everything, nothing else matters. NO, the world does not work that way. Yes, you want to win NCs, but you want to win them with your active participation.