They say diversity is strength, therefore the null hypothesis is that diversity is inherently weakening.
Races very naturally self-segregate. Culture has a biological component,
which means the culture of a different race is never quite a
comfortable fit, and this is only the first of many reasons everyone
prefers to live around their own kind. They do things differently
because what's best for them isn't quite what's best for you. Or, in
extreme cases, what's best for them is very different indeed.
In theory, having two races live closely together will let each benefit from the comparative advantage of the other, perhaps even learning somewhat to do it themselves. In reality both races pick up the vices of the other.
Look, when the Gyew ends up down the well, I'm not mad. I get it. The Gyew
obviously shouldn't have made that deal - look how it turned out, in practice. Maybe don't take risks like that, eh? However, you get vastly fewer
of such deals if you keep the Gyew and the Anglo separate in the first
place. Other Gyews expect it and it doesn't natively occur to the Anglo to do it that way. Put them together: the perfidious Albionite eggs the on the Gyew, encouraging the natural gamesmanship until the Gyew goes well overboard. The Anglo responds with peasant justice, because of course he does. "Ad baculum is a fallacy!" It sure is Mr. Davidovich, but before trying to rip off the goy, maybe learn how they are likely to respond to such a rhetorical ploy...
If you get a racial ghetto, that's not the government's fault or the ghetto's fault, it's the fault of the race. For once, the reason isn't Fascism! Hooray!
Then, if you try to "fix" it with desegregation, you get a dual-racial ghetto. You get sanctimonious blacks and whites going on hypocritical chimp-outs. You get mentally lazy anti-intellectual whites and blacks with no style. Not that white and black are real races, but you still know what I mean.