Leaving a good program to go to what you perceive to be a better program is betrayal of your teammates---a slap in the face--even if transferring is de rigueur these days. It stings. It's one thing when a good player at a smaller program--a mid-major, say---transfers to a bigger, better program, and we see a lot of that. It's quite another thing when one moves from one big D1 program to another, but that happens a lot now, too.
Haley Hopkins was Vandy's best player--a center-forward and true scoring talent on a good team--and two years ago she surprised me and others--including, no doubt her coach and teammates--when she decided to transfer to UVA--a situation quite similar to this one. Vandy is a good program, but UVA is a bit more high-profile. She left Vandy high and dry--and the team struggled to score the season after she left and missed the NCAA. Vandy rebounded this year, however, but it was a serious setback.
I think transferring has been made too easy nowadays--but we're now in an era of player empowerment, for good or for bad. A mix of both, I think.