Criminality will find its way into either an amateur or professional sports enterprise. So I find it hard to call one system more "moral" than the other — certainly on that point.
As to fairness in how the funds are distributed — one can argue ad nauseam on how that should "justly" (or I suppose "morally") work out. In the NBA, for instance — I think the star players take WAY too big a cut of the pie. And the game is ruined thereby. It's too bad for everyone, really.