Well, let's see. Their season average is 92 points per game, and over the last five games they have averaged 89.6. I don't see a big dropoff. I'm sure the loss of Wallace is hurting the team in ways that are harder to quantify, but overall I don't see much change in playmaking opportunities. Or, the rest of the team is able to pick up the slack, in spite of Diaw's struggles. You decide.
You're so intent on asserting Diaw's brilliance that you randomly select any piece of information you can find and claim it to be supporting evidence. First it was that the Suns didn't use him correctly. Then it was that he had tuned out Porter. Then it was that Brown was a brilliant coach who had finally figured out "how to use him properly," as though D'Antoni had not accomplished the same thing during Stoudemire's microfracture season. And now Diaw's regression to the same lazy turnover machine that the rest of us have all come to loathe is due to the team's starting SF being injured. Next it will be that he's adjusting to having a new teammate in Radmanovic instead of Morrison. After that, maybe he'll be exhausted from an emotionally draining season. Or Okafor will get hurt again, forcing Diaw to play out of position.
Lament Diaw's departure all you want, but you aren't going to convince anyone here that the Suns made a mistake in dumping him.