Why don't developers demolish and re-build, instead of (gag) "renovating"?

Dabble in the construction world for a little bit, you will find that it costs a hell of alot more money to tear down a house than to gut it and renovate it. Plus, building primarily with stucco or concrete would cost way to much and if there was a problem, it would cost too much to fix it. Trust me, they wouldn't renovate a house that couldn't withstand the pressure and weights of everyday living, that is why we have engineers. It is not always and only about how a building looks, but how it functions.