So what's the point? All this reveals is the politically incorrect fact that minorities tend to not be "rugged individualists," which is why they overwhelmingly tend to vote for the Democrats, welfare programs, and so on. Minorities aren't likely to go to live in places where they can't extract these "goodies" from the state--that's all that poster you quote from was saying. How is this any of this a mystery?
And why is any of this considered sinister? No one, of any race, is being harmed by legal, voluntary political activity. We still have some degree of freedom of association in this country, and these people are merely expressing a political and demographic preference.