The Suns front office has received some (well earned) disapproval for some of their decisions during the Ryan McDonough tenure. However, the criticism over the trading of Isaiah Thomas is one that is way over stated.
Why was he on our roster in the first place?
It was puzzling then and it’s still puzzling now. Why did the only team in the league with two All-Star worthy point guards decide to sign a third point guard to the roster? The only reasonable explanation is that Ryan McDonough saw such outstanding value in signing Isaiah that he was completely willing to ignore the inherent issues of fit. In the end Isaiah proved to be too good for the role that he was intended to fill (6th man playing 25 minutes a game). The problem that quickly developed of course being that Isaiah was very aware of his over qualification and, as a result, caused problems in the locker room. Jeff Hornacek later admitted to asking the team to get rid of Thomas.