That's like saying that since land closer to Central Park is worth more than land further away, that we should demolish Central Park and replace it with more apartments. Property in NYC would be worthless if there weren't roads you could use to reach it.
Most of the people who go to Manhattan get there by subway, bus, bike or walking (especially the people who have to work for a living), at a fraction of the space cost of those using cars. Access to property is certainly an important part of making that property valuable (hence why property around stations is worth more), but Manhattan spends far too much (in space) on roads for the amount of access throughput it gets in return.