Blaming the state of affairs in NYC in the 70's on rent control is simplistic in the extreme. Rent control (and rent stabilization) are questionable policies for sure, but they were around since WWII, and every tenement owner was aware of the state of the rent roll when they bought the apartment buildings (so the ramifications were built into the price).

The truth is that a confluence of bad policy and economic conditions converged to create the mess our cities were in during that time. Some cities (Detroit, Baltimore?) have yet to recover.