Segregation, in other words.
Whenever segregation and separate-but-equal talk comes up, the (often unspoken, sometimes not) left-wing assumption is that it was horrible... precisely because it denied poor black folk the pleasure of white people's company, intellect and superior example. Alternately, because it denied white people some touching moments and good food.
The idea that some black people would reject white people's company is hard for many SJWs to grok, and often gets treated as a symptom of a problem as opposed to a 'real' conclusion. You know -- 'You don't want me around? Even though I attend Black Lives Matter rallies and I hate Republicans? Oh my goodness gracious, you poor thing, clearly the difficulties of your circumstances have driven you mad!'
As for the idea itself, I think it's a bad one for a lot of reasons. I also think it's an idea whose approval/disapproval rates will map heavily along geographic lines if it ever got aired outside of a tiny audience.