One common truth that seems to have been totally disregarded in this whole Miles saga is that Portland helped Darius Miles by medically retiring him.
Miles did not fit with Portland’s culture. Much like Rasheed Wallace before him, Miles was tainted (fairly and unfairly) by the Jail Blazer era. Simply put, while he remained with Portland, he could never really recover his image. Now, Miles is seen as a tireless worker who wouldn’t let the man (or doctor) keep him down.
Miles did not fit with Portland’s roster. Portland needed to get younger, they needed to give rookies and sophomores a chance to shine and Miles was neither. Once he was injured, his shot of actually contributing to Portland’s roster was drastically reduced. Put it this way, if he was on Portland’s roster he would be sitting by Martell and Ike.
Miles was not getting better in Portland. This is related to point #2. Miles was not going to get playing time and, therefore, did not work very hard to get back on the court. His body was not getting better, while he literally wasted away in Portland. The medical retirement gave him a reason to come back. It gave him hope of resurrecting a once promising career. He has worked hard to get back on the court - that would not have happened if he was still with Portland.
Portland gave other teams a reason to give Miles a chance. Pretty self-explanatory.
Portland increased his salary. With the NBA admitting that they denied Portland’s waiver claim, Miles has a legitimate argument that a team was willing to pay his salary for the entire remainder of the season. If he gets cut by the Grizzlies, he can say that he was denied a chance to make some more money.