Nah! Really?!

Wario is designed to be plain annoying in every way. He is supposed to be a douchebag, but not an american.

I don't see how Olimar can be annoying.

*Sigh*

I remember the days when Wario was just as badass as Bowser...

If only we had someone with the music of the Runaway five.

Do they?

No, Wario is how everyone else in the world views Americans. =P

Seriously though, the "reverse Mario" explanation sounds best to me. Mario is an all-around good guy who does good stuff and has heroic features, while Wario is an evil inversion of all his features. Some of the jokes played on him might be stereotypical of Americans, but I wouldn't think too much of it. You guys are so common in popular culture, that you get your fair share of good heroic types as well.

Wario is more of a pre-WWII anti semitic caricature portrayal of a Jewish person.

Japan generally likes America and American culture, or western culture more accuratly. If you look at their fashions alot of it is copied from american styles, the stupidly large baseball caps and so on.
Wario was designed to be basically just an anti Mario and is supposed to be obnoxious and annoying.

Dont forget, Mario himself is supposed to be an american. 

Wario and Olimar are awesome. I doubt Japan views america as a nation of wario's.

Has nobody here even played Super Mario Land 2: Six Golden Coins for the Game Boy? It really explains everything.

Wait, are you suggesting that the US isn't entirely populated by flatulent bikers who wear pink pants?

Earthbound. DS. NOW!