JS, the question you pose is ethical or normative, and I have no answer for that side of it. My economics training only tells me to look for efficiency criteria, and I can tell you that letting insurance companies discriminate based on neighborhood or genetics or whatever else would lead to lower prices for consumers in general (at the expense of less fortunte folks). The important question is which of the two (efficiency or welfare of the disadvantaged) is more important to you -- and of course there's no set answer to that.

Anyway, not the time nor the place.