1) Came into the league that has rich history with a giant CHOSEN tattoo. Chosen to do what? It had religious like implications, like the league was doomed and he was the savior.
2) Is the most physically gifted (including durability) nba player of our generation, yet whines and flops more than most players. He often pretends to get hit on the head or neck, which are serious areas, and replay shows that he wasn't touched. Imagine someone of his size doing that in a pickup game with you... you'd think they were the biggest P@#($ (wimp).
3) A significant portion of his effectiveness is from athleticism, yet people want to dub him "the greatest." The greatest at what? Compare him to someone like Bird, who was a significantly better shooter, rebounder, and slightly better passer... oh and Bird had a better defensive win share rating for several years. The one year Lebron lost weight and came back super ripped he was a mostly average player... until he bulked back up.
4) When people think of greatness, they don't think of someone who doesn't seem to understand basic traveling rules. Lebron routinely gets away with 3, 4, and 5 steps, and when traveling is once in awhile called on him he seems incredibly perplexed.
5) Everything he says and does has been thought out for months, which I can't blame him for given the media, but he's all about his brand. Very little about him seems genuine or relate-able.