^^^^^
"Mr Gorbachev tear down that wall!".
Vandalism is not a reason to save a structure, ESPECIALLY when they don't own it. Now if they own it, they could whatever they want. They could piss on the walls and add a yellow facade.
In NYC, there are plenty of spots that allow graffiti on the walls. It could be in the form of an advertisement or a form of public art, but in the end, the owner of the building has the rights. So long as what they are doing abides by the codes and regs of that parcel, the owner is perfectly in the right. In the case of 5 Pointz, they were justified.