c) On Wikipedia, America is King. The rest of the world finds itself having to explain why such-and-such article should be written from a NPOV rather than an American one. This is not deliberate, there is no organised campaign by Americans to corrupt the encyclopaedia, it's entirely unintentional ... and that's even worse.
The Wikipedia has problems, of course, like Parisian Pedants who have something against good old Québecois, but I've not noticed the bias you're talking about.
Maybe you mean the english-language Wikipedia.
Cheers, Daniel