So all of this basically just confirms what we already knew:
1. Ray felt insulted that Doc started a player [Bradley] who was a better fit with the starting linup than he was.
Ray's net off/def rating was +3.1, meaning the Celtics outscored their opponents by an average of 3 points per 100 posessions with Ray on the court.
Bradley's net off/def rating was +5.6, meaning the Celtics outscored their opponents by almost twice as much when Bradley was on the court compared to when Allen was on the court.
Clearly the Celtics had a better chance of winning games with Bradley on the court, so if he were as unselfish as some people seem to believe (and truly wanted to win above all else) he would have accepted that and bought in to the bench role. In fact if that were true he would have WANTED to come off the bench, knowing that he increased the chance of his team winning.
Look at Jason Terry as an example - he's always been a top 5 player on his teams, yet he has bought in to the role of being a leader off the bench. He understands that winning is more important than ego, and that you don't need to be a starter to be valuable. In his championship season in Dallas he knew that even though he was coming off the bench, he was still the 2nd or 3rd most valuable player on his team.
Ray seemingly felt that the role on the team measured how valuable he was - as if it's all about labels for him. Sounds like he couldn't comprehend the fact that our bench was desperately lacking scoring power, and that a shooter of his calibre would have been far more valuable with our second unit than it was with our (already very offensively potent) starting lineup.
2. Ray felt insulted that Doc chased a better player [KG] more aggressively than he chased him
This is like Pippen getting upset because Phil Jackson pursued Jordan's contract extension before going after him.
KG is clearly the better (and more valuable) player to the team. All you need to do is watch pretty a few games from last seasons playoffs to see this - along with Rondo, KG pretty much put the entire team on his shoulders and carried them to the ECF. Plus pretty much everbody on this Celtics team acknowledges that KG is the reason why they have been a top 5 defensive team every season since 2008.
Pierce is clearly the centre of the teams offense (unless you argue Rondo is) but one way or the other Ray clearly doesn't have the same degree of impact on this team as Rondo, KG and Pierce did...so this is just a case of Ray's ego eclipsing his common sense.
3. Ray felt insulted that Doc wasn't running enough plays for him, and hence he wasn't getting enough shots
This is probably the only part I can SOMEWHAT sympathise with, because Ray obvious knew he was still an elite shooter and yet Rondo, Pierce, Bass, KG and even Bradley all had higher usage rates than Ray.
When you have Rondo, Pierce and KG above you for usage rate you can probably accept that, but when you are as capable a scorer as Ray and have Bass and Bradley getting more plays called for them than for you...I can understand how that would be difficult to swallow.
Limited as Ray was at times, there's no denying that he was at least the 3rd best offensive player on the team last year, so being ranked 6th in usage rate would be a bit humbling for a player of his ability and reputation. Granted, the usage rates for Bass and Bradley were barely above Ray's at all...but the fact that they were above his period would have hurt.
Plus Bradley was a second year player (not known for his offense) and Bass was playing his first season in Boston. Ray had been there battling with this team for the last 4 seasons and is arguable the greatest shooter in history, and those guys are getting more touches than him? If you put yourself in his position, that would be hard to accept.
That said, there was obviously a reason why the 2nd or 3rd best offensive player on the team wasn't getting many touches. It probably had to do with the amount of time Boston would loose off the clock while the ran ray of multiple screens trying to free him up for a shot. For Bass it was a simple pick and pop, and for Bradley a simply back-door cut - both are quick and easy plays to run by comparison.
Ray should have realised and understood this, but i'm sure it's much harder to see clearly when you are in that situation yourself.
Either way there is really no excuse for the first factors, and I seriously doubt Ray's usage rate will be much (if any) higher in Miami.
Even if you COULD justify all of that, there is no justifying his subtle public badmouting of the team he apparently still considers himself 'spiritually' a part of. That's just unprofessional.