Presented in 'evidence' of this non-falsifiable hypothesis were 'questions' like, if Western Civ isn't superior, then where are all the black scientists? Where are all the Muslim poets? Where are all the Hispanic inventors? Counter-questions like "Who decides what activities make a civilization superior?", "How can you objectively claim that one type of art is superior to another?", or "What about this or that black scientist, Muslim poet or Hispanic inventor?" were met with the usual rigorous retorts, like "Sez you", "They don't count", or "YOU shut up." And because the primary thing that Objectivists and Libertarians value over everything else -- the thing that they seem to believe is the ultimate justifier, the unanswerable argument-settler -- is money, eventually someone would chime in by saying that the way you can tell that Westerners (that is, white people) are superior is because if they aren't, where are all the black billionaires?
This argument picked up a lot of steam at the dawn of the internet age, because racists and free-market crazies took to the World Wide Web like flies to shit. It even held traction when there were an increasing number of black millionaires (because it doesn't count if you make your money playing ball or rapping), and even held on when the very success of the internet turned out to be increasingly the work of Indians, Koreans and other undesirables (because, I guess, their customers were white, or something). Eventually, it fell out of favor when it became clear that flagrant racism wasn't the best way to get people to join your fun club, and it eventually got relegated to disreputable corners of the internet like Yahoo! Answers (where you can Google "why are there no great female _______" and find a million such screeds, unless what goes in the blank is 'Madonnas' or 'whores'), Usenet, and the occasional attempt to slide it into a place where decent people hang out, in the guise of a tirade against multiculturalism (examples here, here and here). Or, you could just go Reason.com and do a site search for "political correctness".
Still, just because it's no longer socially acceptable to say something doesn't mean people stop believing it. Just as the election of of Barack Obama and its concomitant promise of a 'post-racial America' has led to a new renaissance of gross public racism, I'm sure that there are still large chunks of the radical right who still secretly mutter some variant of "If they're so smart, why aren't they rich?". (A question, curiously, that they never seem to ask themselves.) I have to wonder: the image of Mexicans as welfare-cheating, freeloading, law-flouting bums heats to the boiling point, at the same time a Mexican becomes the richest man on Earth. (And a half-Arabic Mexican, at that! The horror!) Haiti is held up as an example of the dependency, neediness and incompetence of blacks, at the same time that Gatwick Airport is sold for a billion dollars to a company headed by a black man. (And a black African, at that! The shame!) China is condemned as a nation of gangsters, thugs, and retrograde, backwards-looking despots, at the same time that the Chinese continue to buy up the debt without which our country could not economically survive. Are the Objectivists refining their argument, or just looking for a new set of exceptions?