I think it is important to collate the might-have-beens of history, in order to show future generations and young people that things need not have been this way. Urban history is especially replete with might-have-beens and counterfactuals, e.g. cities where freeways weren't built through the inner city as opposed to ones where they were. Mostly to do with racism, class prejudice and the desire to make homes for living in into speculative commodities, of course.