There's NYC and there's NYC. Manhattan is a small part of NYC: Staten Island, you must have a car. Large swathes of Queens and even Brooklyn have no pub transport (buses can be pretty awful due to traffic although they do exist). I think that's a big block of people opposed. Another political consideration is that the State of New York has control over elements of policy that would otherwise be anti-car. For example, the congestion tax they wanted to bring in, it was the state government that killed that.

I still agree that congestion control, disincentives for car use, wider sidewalks, all should be done. Some of us wish NYC could declare independence so we could choose our own policy, but that's a different story...

Perhaps because while most people don't own cars, they do depend on them (even if only in special circumstances) in the form of cabs.

If that were what was mostly going on there'd be a heck of lot less on street parking. Essentially none of Manhattan should have any on street parking at all. Some standing zones for deliveries and pick up / drop offs (but not loitering forever, I'm looking at you black cars) and that's it. You'd be able to cut width of a typical street by 1/3.

You don't understand why people might like cabs, trucks, busses, and emergency vehicles? People don't drive their own cars already.

None of those need street parking – in fact, you'd dramatically improve their experience if the parking lanes were replaced with dedicated transit / bike lanes, etc. and a few dedicated taxi/etc. loading spaces.

One of the reasons for this is that street parking is usually subsidized well below the market rates and so drivers will spend a significant amount of time looking for a cheaper parking space rather than simply parking in a garage, and they're using road capacity until they either find a space (and then block the lane while they slowly attempt to parallel park) or give up and pay to park off-street:

“In 2006, surveyors interviewed drivers stopped at a traffic signal in the SoHo district of Manhattan, and 28 percent reported they were cruising for curb parking. A similar study in Brooklyn found that 45 percent of drivers were cruising. The same results might be found on many other streets in New York because off-street parking is generally far more expensive than on-street parking. In midtown Manhattan, for example, the price for the first hour of off-street parking is often about $20, while curb parking is only $1. Parking for an hour at the curb saves $19, but drivers first have to cruise to find a space on the street.”

http://shoup.bol.ucla.edu/CruisingForParkingAccess.pdf