[yummyfajitas]

Thus, attracting more affluent, less intelligent, and typically more dickish yuppy types

Therein lies the real reason. "If we allow new construction, people who are different from us will move in!"

By the way, companies building rental buildings rarely construct them poorly. It's just bad business - once the building starts to leak, renters will move out, and it's the responsibility of the management company to fix it.

As for shipping projects out to jamaica, I didn't mean to single out Jamaica. You could spread it around all the cheapest areas in NYC. But yes, you are correct that it is unfeasible, since people will fight it for cultural reasons.