You can't have the cake and eat it too.
It didn't work out, James chose the easy way out, to join Wade's team. Clubs let players go all the time, and players leave all the time. Loyalty means nothing nowadays. Fans burning his jersey, and owner writing that bitter and tasteless letter, are uncalled for. What have they been? Welcome to professional sports! But the legacy for LeBron would be different, winning in Cleveland vs in Miami with Wade and Bosh.
LBJ had tools and chance to get close to MJ, if he could bite the teeth and go through the darkest moment before dawn. He may succeed, or may fail. But he doesn't do what MJ did. Now he's not only further away from MJ, but also away from Kobe, in terms of competitiveness.
Nothing to blame LBJ, it's all business. He's a great great basketball player, in Cavs or in Miami, nothing more and nothing less. But he's just not a great leader.