Much of the property in NYC is just parking money into fixed assets... doesn't even have to be income property. I'm not sure the govt is capable of fixing the issue, short of separating corporations from personal liberties legally (via national legislation) and legislating usage requirements for corporate owned land/property. Both of which would be VERY hard to do legislatively.
If there's no height limits, someone owning an empty condo shouldn't stop other people from living in the same building. They're paying property tax too.
