Bah, you people like Western Europe
too much.
I get so bored with "I like swords" class and "I shoot fireballs and fly and teleport" class. The monk is the only refreshing breath of air sometimes when it comes to D&D from all the Robin Hood-esque classes out there.
And whacky Shaolin-style powers? Hm.. I'd say wizards and sorcerors are more whacky than any monk build you could crop up.
The monk fills a nitch that says "Asian" on it, but I don't think it entirely breaks the suspension of disbelief. The difficulty of the class really only comes in integrating the culture of the classes... but don't most parties already suffer from that? If not, I think they should.
For instance. I hear too many stories about campaigns involving neutral evil rogues and some shining paladin all travelling together. And meanwhile the rogues are out having a good time causing mischief under the paladin's nose. Or about the party wizards, who probably shouldn't really be interested in fighting anyway, that commonly travels with their buddies, the Fighters and Barbarians. But the game still works because, at least sometimes, the group decides that they'll roleplay how these weird characters manage to put up with each other. I don't see how the monk can be much different, other than it's Asian.
And the fighting stuff... to me that's no more wild than armored paladins fighting dragons, and fighters some how defeating armored opponents with razor sharp swords, with fire I might add. It all doesn't make much sense to begin with. Or the rogue who uses a dagger to beat the most dangerous opponents all the time. That's pretty whacky too. Do you house-rule that a halfing rogue must use a larger blade or heavy club when fighting an ogre? And if not, do you just pretend then that he somehow leaps in the air and stabs the guy's eyes out all the time? Sounds like he's doing whacky shaolin stuff to me then.
And swashbucklers.... that's one of the most "whacky" classes I've seen. In fact, their not much different from a monk in concept. Except the personality. They're "adventurers" yet they're also able to do near super-natural things with their flimsy swords. Intelligence modifier to AC? Sneak attack damage. And there's more. It's all based on doing whacky things with a sword. I guess you could argue that it's okay because it's "western," but when you pit these guys against some of the creatures or people they face... that's really pushing the suspension there. At least for me. "I fly up and, put my rapier into the dragon's... uh.... eye!"
I would make a case that something like the Wu Jen is probably a bit too culture specific (i.e. not vague enough). But the monk seems generic enough to me along with the other classes in terms of "what it's all about." A fighter could be as North England as possible, or Arabian in nature, or Egyptian, or even Greek or Roman. A monk, likewise, could simply be a man in the same area or culture, that had no access to weapons and armor. Just because he's learned to leap in the air and kick doesn't mean he's Asian. They're not the only people that could ever figure out how to kick or punch.

Just the most widespread and tradition-oriented. Why not have a character who starts such a movement in your world?
I just find it humorous that there are so many threads that crop up here that talk about "breaking stereotypes" and playing "interesting characters" or making "unorthodox paladins." And yet once a character throws a punch instead of using his equally cheap dagger, the whole fantasy is shattered. But that's not a fair judgement on my part. D&D was meant to be played the way we like it.
But, just one more thought. Is a monk really that far out when put along side a Wizard, with his 120-page spellbook sitting on the table that basically says "Wizard's can do anything, if only they put their mind to it?" There's something about flying wizards that breaks the suspension of disbelief for me all the time.

Plus, I don't see how the wizard or sorceror of third edition matches up to any of the Western concepts much anymore, aside from the ability to cast magic. Which again, other cultures, like Asian, had similar concepts. The 3.0 wizard is so generic and "all-purpose" that he hardly retains any kind of 'culture' at all. But I guess that's why he fits in so well...