Rooftop Koreans work because they are a gang. No, they are a criminal gang involved in prostitution, illegal immigration, money laundering, etc.
The other factor is 'Keh'. Look that up. Keh.
Keh is Koreans getting together with other Koreans and pooling their money. Organized by women. Say 10 couples. For nine months, you present $10,000 to one of the members of the Keh. He gets a $90,000 interest-free loan. On the 10th month, you get your $90,000 back in one chunk. So you can't pool $90,000 in one month, but you can get it one big chunk if you do this. Just save your own money, right? Well, if you draw the lot on the 8th month or earlier, you get $90,000 before you could have ever saved it. The last couple in line doesn't really lose anything because it would have taken them that long to save their money anyway. You literally have a 9/10 chance of getting $90,000 before you could ever save it. Those are good odds.
Plus if you get the money, you have throw a home-made banquet commensurate with the amount, so you get a free meal on the Keh day.
It's a kickass system, but what's to prevent the first 9 Koreans from saying "Got my $90,000, seeya fuckos!"?
Because Koreans don't fuck around with that shit. Korean is a difficult and little-spoken language, and it's hard to lose the accent. So if you get ostracized by the Korean community, you're fucking fucked. You are going to be doing dishes at a Chinese buffet and Chinese and Koreans don't get along.
So, as I've said before, countless times:
Koreans take care of themselves, Whites do not take care of themselves.
Blacks march and get their shit, Whites don't.
Jews watch out for each other and give each other jobs and persecute people who offend Jews. Whites don't.
Native Americans start lobbying groups to help other NAs. Whites don't.
And in the same way:
Koreans, Blacks, Jews, Indians, and everyone else watches out for each other. Whites don't and wont.
Draw this out to its logical conclusion.