This loss is heavily on James shoulder because this is the team he wanted.
He wants to play with a bunch of 2nd fiddles. Guys with the Gasol, Bynum, Odom type personalities that dont really care to be the man on the team. James doesnt want to play with guys who he is have to "share" with. This is why I dont see James, Bosh, or Wade teaming up. I see James wanting to play with Boozer and David Lee types surrounding him.
Shaq and Kobe didnt get along. The Shaq and Wade duo didnt last long either. Look at a team like Orlando. You have bunch of guys who dont care to be "the man". It is understood that Howard is the man on that team.