Obviously Wade did it to send the message to Kobe that the kind of stuff he likes to pull on other players doesn't work on him, and that he isn't gonna get away with it clean. Basically a "watch your step" and "not in my house" kind of message and to show Kobe not to get too cocky. We all know Wade doesn't respect Kobe at all and thinks that he deserves the spot to be the best SG in the league, especially from his previous attitude and comments pertaining to Kobe through the years.
I would be able to relate to him in the slightest if it was in a playoff game but a hard foul in a all star game where everyone's playing no D and just letting other people do a dunk show for the crowds? That's unacceptable, and as said before, Wade broke the All star game's silent code of conduct when he pulled that crap. He felt justified in doing that from his comment after the game and the fact he didn't even bother to show any concern or apologize to Kobe. Completely dirty, disrespectful, and horrible sportsmanship, even in the NBA standards, just from a player to player.