I bet what OP is seeing is in response to that. Detroit is likely a much more common search, so to keep that populated, they just collapsed all of Dearborn into it.
I'm not saying that's not the root cause, just that it seems like a backwards implementation if so.
I think it can make sense from a business standpoint. It is unfortunate it hurts other hosts who have nothing to do with it. But I would guess this is just temporary.