Players hardly show any loyalty to teams when they negotiate their contracts, and that is okay but the corrollary is that the team should not owe any undue loyalty to the players when their talents wane and they become a liability to the team
I actually put the onus on the declining player to do the right thing and tell the team that it is okay to trade him for a better deal. Negotiating in the NBA should always be at arms length - this after all is still about the bottom line, and that is ruled by winning.
If the player is not bringing it on the court, he should be man enough to retire or understand that he will be moved.
Remember, that when the Cs were losing PP was ready to bail!