aesthetic is defined by the wealth of people living in them. Rich people change decrepit areas to expensive urban centers. Medieval italian cities must have looked like crap, literally, with all the dung in the streets, but look at them now. And venice was not all palaces when it started.
american cities were optimzed for the car, but what about now that the car is receding and business districts will cease existing? Organically-grown cities adapt better to the passage of time