Actually, that isn't how it turns out at all: there is no "ghetto" established, as the laws that the prevailing governing body passes will apply to the entire incorporated area (city, county, state, whatever). The key difference is that without the gerrymandering, there will be no voice in that governing body to represent the extreme minority's interests at all. So it's actually anti-segregationist, since it gives the minority a stronger voice than they would have otherwise.
That's a horrible way to fix the problem. It's better to have a proportional system, where parties are awarded seats in the government/state/county in proportion to the popular vote. The problem only occurs in winner-takes-all systems in the first place.
If we accept gerrymandering to give certain minorities a vote, we're also giving politicians an excuse for abusing the system to further their own power.
And yes, it's segregationist. Segregation means you separate ethnic groups. Having good intentions or giving the group a stronger vote doesn't change that.