Just that it's one set of zoning laws or another. It's not like we're living under some laissez-faire regime where developers and capitalists can build anything, anywhere. Personally, I prefer the New Urbanist mixed use code. I assume you don't.
An as for Detroit, I said "shaped" not "founded." I'd argue that Detroit is more shaped by developments over the last 40 years than by anyting that happened in the previous 260.