I start with the assumption that to get a useful player (say someone like Camby) was going to cost at least a 1 Rnd pick plus maybe a young player (Bradley, JJJ, Moore). With that, I would rather keep the pick/player vs. a rental.
The second assumption is that we could not get enough back for Ray to beat who we might be able to sign with the space this off season. Much like we weren't willing to give up a good pick or young player for a rental vet, I don't think other teams were either (other than the Lakers who were giving away picks left and right).
So based on that, why would we start selling off the parts of the team? We have a very marketable team that is going to likely make the playoffs. People will still buy tickets to see KG, Ray, etc but if we dumped them, we are not nearly the draw and no better off in the long run (based on what it appears we could have gotten back).
This was a decision based on part business and part basketball. Let the big 3 play out the tour and do your wheeling and dealing at the draft and free agents.