For what it's worth, I do think that Colangelo has a tendency to oversell, but I agree with Jeff that every GM sells and is asked to do so by the organization. I'd be willing to bet that the top of the organization considers Colangelo's selling an asset. For fans, it's a bit different story, but I see the pragmatism behind it.
I think the unfortunate thing about Colangelo's vision is that it never really came to fruition. If it weren't for some bad breaks, the Suns could've been NBA champs a couple of times. You see how the league has become increasingly focused on guard play and pace. Yet he left Phoenix and came to Toronto where he never really put that same vision into practice, perhaps because of the talent on hand. Now the league has made rule changes to re-emphasize defense, and out of absolute necessity he will have to go the traditional route to build this team.