I lived in an area of the Bronx that required taking a bus to get to a train as well. Still, somehow, most people (even older people) found the energy to do it.
As far as residents of Manhattan are concerned: When I lived in NYC (from 71-95) I distinctly remember that Manhattan residents got a special deal on parking. If I remember correctly, they got a BIG break on the excise taxes everyone else had to pay to park in a commercial lot. I think it was like 24% for non-Manhattanites, but only the regular 8.25% sales tax for those who lived there. So, their sweetheart deal is going away (if hasn't already - it's been a while), and you're not going to get any tears from me.
Also, if you're worried about older people and people living in subsidized housing, let's talk about that. Let's talk about the fact that the crosstown buses are damn near unusable because of traffic congestion caused by autos coming in from off the island, forcing older people who can't walk long distances to wait, and wait, and wait. Let's talk about the pollution that all those extra cars are causing, which makes it harder for them to breathe and drives up the medical costs of the people living there. And let's DEFINITELY talk about the people who contribute to this huge problem in the name of their profit-generating enterprises, but can't stand the idea of chipping in a measly eight bucks to help fix the problem to which they are contributing.
And no, the limos, Land Rovers, and Beemers won't be as affected as the elitist snobs I grew up with (and apparently you didn't), but the coffers of the city will benefit from their voluntary user fees they will have to contribute.
By the way - this plan is working out GREAT in London. According to
a BBC report: Traffic has been cut by 18% and delays were down 30%. Can you imagine the quality of life increase that would represent for the people who choose not to drive in Manhattan?