Did you see Nowell when he was given playing time this past season? The best pass he threw was one right in the opponent's hands.
There were about a half dozen things going on that you know nothing about. Of greater importance, you're jumping to a conclusion (that because Mahaney seriously underperformed, Nowell had to be a better option) based entirely on conjecture.
Maui hurt this team on many levels, one of them being that it destroyed the confidence that a few players had in their abilities and in some cases things continued to deteriorate. There were also injuries in play, some kept people out of games, others just limited some players slightly.
I can assure you that if any player demonstrated that he belonged on the floor for serious minutes, he would have received serious minutes.