Wherever the blame is placed - and I am not suggesting that Colangelo needs to be exonerated - the biggest issue with the club is an absence of any sort of long-term vision. Whoever's at fault there (ownership could be demanding immediate results, for instance) is ultimately responsible for the predicament the team finds itself in season after season.
No matter which way of team building one supports, the only thing that has to be common for all of these ways is stability. You have to have good players, both individually and fitting well together, but you also have to give them good coaching staff and time to play together and grow together as a team, to learn each other's strengths and weaknesses and become a true team, a collective rather than a collection of individuals, to achieve any sort of lasting success. The absence of this approach over the almost 20-year history of our franchise is glaring and obvious and it is absolutely something that separates us from any NBA success story except, perhaps, Miami's latest "steal the stars" foray.
Whoever ends up running the club should have the balls to go to the owners and explain this to them and demand the long-term commitment to doing things right.