No one "deserves" a ring. It's not a God given right. He earned the ring. And people have reasons, legitimate in your or my opinion or not, to "hate" LeBron. Believe it or not, not everyone just hates him because it is the cool thing to do, and even if they do, that's their prerogative. It's not "childish" to dislike a guy that went against what you believe in.
People are going to believe what they want to believe. They aren't going to try to make you hate LeBron, so you shouldn't try to make them like him.