I can see arguments for not retiring KG's number. He was vital to winning one title. But just one. Then he hurt his knee, and never really got back to where he was. Neither did the team. As I recall, the ownership maybe decided one championship was enough, and went under the cap--not re-signing Posey, Perkins and others. Posey got some ridiculous offer from N.O.? was it? And Wyc seemed to think defensive players like Perk shouldn't be paid. Sometimes you have to learn the hard way. And then they lost to Miami in the East finals when Bradley hurt his shoulder. Lucky Miami. The Celtics had them beat.
I also think KG has an identity with the Timberwolves--he was drafted by them and played most of his years there. Perhaps the Celtics think retiring his number would be an affront to them.
Un-retiring numbers from the great Championship dynasty teams? Is that a joke? All the great ones are right up there where they belong. I saw them all play.