Why does everyone say lebron is not good because he got no rings?

that's what i mean, rings are for great teams, and lots of great players dont have rings, on the other hand, robert horry (no disrespect) has 7, thts more than michael jordanand all those guys up there put together, and he's by far not the greatest plater to play the game, that's why i respect lebron's decision (joining my favorite team since 05 didn't hurt), although i don't like the way he went about it, it's true that one player cannot get the ring by himself, that's why the mvp is for the best player, and the championship for the best team