General manager Brian Cashman has had near-complete control of the Yankees' baseball operations for about a decade now. Before that 2005 extension, the Yankees' management was a kerfuffle of confusion, as George Steinbrenner went back and forth between trusting Cashman and going with the instincts of his Tampa-based colleagues. The times have mostly changed since then, and while occasionally management will still reportedly go over his head on deals (the Rafael Soriano and Ichiro Suzuki signings come to mind), Harry Truman would say the buck pretty much stops at Cashman.
In those 10 years, the Yankees have not produced many quality minor leaguers.