It is a moral/ethical thing. If you keep encouraging it, the bad behavior will continue.
Dude, he's been playing this way since 1977. In fact your comments sound like hundreds of columnists, commentators, that have spoken about him since then. Its a little to late for that, especially since tennis basically let him do whatever he wanted his entire career. He was/is bigger than the game, & tennis is a sport that depends more on stars(I read that the Thailand Open was a bust this year, since Federer, Roddick etc didn't play) than any other sport. Jmac helped make the sport bigger than it was, he deserves to do whatever the hell the wants, as long as people want to see him.
Do you watch any other sports? There are plenty of hotheads in team sports. Pro sports isn't the real world & it isn't all fun & games.