If you want a prayer of resigning DeRozen you can't subject him to putting his heart and soul in to a team which makes a guy like Bargs the focal point.
It sends the wrong message.
Busting your hump up and down the court and in practice to win games but to loose cause a guy wearing the same color jersey as you lets himself get out rebounded or scored on is something good players can't reconcile.
So they vacate.
Bargs has the talent to be a top flight big but his effort/interest is there about 60% of the time. He looks like a millionaire now. Some guys get rich and don't loose the fire - they live to compete.
Bargs is not that guy - neither was Vince Carter... DeRozen Might be.
Garnet Kobe Lebron are guys who play just as hard if they had a billion dollars as if they had one.
Remember players are more loyal to each other than they are to a city. Bron Wade and Bosh would have played CHI MIA NY CLE as long as they were together.