This take on the matter, from a USA Today article entitled "Buffalo charges ahead into the past", I found interesting:
Because there's no reason to tear down a building if there's nothing to replace it, Buffalo has benefited from "preservation by neglect." As Harvey Garrett, a neighborhood preservation activist here, sees it, "Buffalo was rich at just the right time" — 1870-1914, when great architecture was still relatively inexpensive — "and poor at just the right time" — after 1950, when many older buildings in cities with better economies were demolished.
While St. Louis was not "rich" in the modern period (1945-1975), federal monies were flowing in and the city was at its boldest and most progressive peak during this period. This does, of course, explain the part of St. Louis's culture that is so willing to part with old neighborhoods and housing. But countless cities, including ones often considered down-and-out like Buffalo, have done better by taking advantage of being more intact, having fewer interstates and other obstructions in their urban built environment.
My previous post was not meant to condemn St. Louis outright as a place with no hope to improve itself. My point is we have farther to go so we have to push even harder. The neighborhoods that remain preserved in St. Louis are outstanding, but those that are some of the most threatened today (Hyde Park, St. Louis Place) should be some of St. Louis's greatest. We can make this happen with sound urban planning and a refusal to accept mediocrity in urban design in the whole of our city.