Maybe in some cities, an ethnic neighbourhood (like a Chinatown)can be a ghetto, but in others it's just a commercial district. I live a few blocks away from a very tiny Little Jamaica, for example. It's just a few hair salons, delicatessens, a clothing store - no housing. It makes sense to group businesses that way. When I pass through the computer district, I don't expect to see web designers hanging out of all the apartment windows speaking their language.
