Free Step Dodge

I can tell you the honest reason but it will probably just piss you off. I know if I was black it certainly would.

MJ had emotional reasons, but for most celebrities it's because white skin is seen as more attractive in many parts of the world. As people become more famous, they try to broaden their appeal through this method.

In the case of Zack, it's because the Japanese not only fall under this category, but are also downright racist as hell, to put it bluntly.

The exception to the rule are workaholics like Samuel L. Jackson who just don't give a fuck.