Your strange fixation on Isiah aside, there are a lot of weird quirks with Melo's career. There was the report starting that between the end of the NCAA tournament and the NBA draft that he didn't even pick-up a basketball. He seemed content to play for a lousy Knicks team that outside of one solid season, was mainly a train wreck and Melo seemed fine with scoring a lot of points and being a star in NYC, during an era where his contemporaries were bulling their way to new teams in order to remain perpetual contenders. Then once he started to decline he was a disaster in multiple stops, and was pushed out of basketball. Why would someone who appears to be genuinely loved and respected by his peers be out of basketball, until washing up on a desperate Portland team?
How Melo has handled aging is an interesting glimpse into his career as a whole. On paper, Melo should be a great role player because even with diminished speed and athleticism, he is so talented he can bring a lot to the table, especially in a league that has gotten smaller. When he was a FA people would talk themselves into the idea that he could help a team because he could be a good rebounder, screener, corner three guy and help a team. The problem was that Melo wasn't interested in doing things like rebounding and setting screens and not being the go-to-guy. Sure he had the skills, but he was used to being the star and didn't seem interested in doing all of that hard stuff.
I do think that his time away from the NBA has maybe humbled him a bit and his run in Portland has been overrated by some and underrated by others. I've never really been a Melo fan, but it is more fun seeing him involved with a team again. If he gets hot in game against the Lakers and makes like, 8 three pointers and scores 30 points it will be a great moment.