It is nonsense, when you look at things in aggregate.
Of that list, three of those players were not extended the option of returning. They left SU because they didn't have a choice [two of whom expressed an interest in returning but were denied].
Counting Ennis and Grant doesn't substantiate your argument, and is a huge reach.
So we're talking Melo more than 10+ years ago, Greene, Flynn, Waiters, and MCW since 2003. You could also include Wes in there, but I tend not to since he was a transfer in, and hence an unusual circumstance.
That means that every other player recruited during the last decade fits the mold of what I described above--players who in general were good system fits, who tended to stay for the entire duration of their careers [or transfer out]. But program guys nonetheless.
We've had a couple of players jump to the NBA early, but far fewer than many other top programs. Which was the point. We recruit a couple of elite guys, and cluster them with system fit role players, who often are also good athletes and develop into good players over the course of their four year career here at SU. Sometimes those elite talents pan out and live up to the hype [MCW, Waiters], sometimes they fall short [Fab / Harris / Rak / Coleman]. But the four year players are often as important [GMac, Andy, Onuaku, Rick, Scoop, Kris, Fair, etc.] to team success.