Just speculation on my part but her quote here
"My experience at Duke has been amazing,” Stevens said in a press release announcing the departures. “I would like to thank the staff and the Blue Devil community for all their support over the last two years. At this time, I feel it would be best for my basketball career to go in a different direction."
This says three things, first she took the high road by thanking the staff when the entire outside world knows there is a problem within. Second she realizes her game is not going to improve under the current staff and last but not least someone of her caliber would probably like a shot at a NC. I can't think of a better place to achieve the last two.
Stevens, Salvadores leaving Duke women's basketball program