Nobody denies the possibility that the problem is that players play better with more time and better teammates. Playing next to a great player and a couple good players will make you play better even if they have nothing to do with you simply because of how possessions are used and distributed.
LeBron DOES make his teammates better because everyone is afraid he'll just storm to the hoop for 40 points. Kobe absorbs all the shitty possessions and jacks them up himself, allowing the rest of the team to not make mistakes.
Iverson's value came out of playing on a team full of worthless players so somebody had to shoot.
The problem with the Kobe MVP myth that started when the Lakers got good again is that Kobe didn't change his game at all, he just played with better players. The "selfish" Kobe was the one that pushed his team beyond where it should have been, like Wade, and LeBron before he had a real team. He does the same thing along side two "stars" (Gasol and Bynum, plus Odom) and suddenly he's "unselfish" and "making his teammates better." It's like Stackhouse in 2001-02 when he played worse but people considered him to be playing better.
Chandler's superior shooing came from him being put in a more proper role, West created the low post shots, Chandler hit the boards and scored on put backs. And then also focused on playing defense. Did Chris Paul set up shots for him? Yeah, but without West drawing attention it would not have happened. This range is the important stuff.