Your lack of desire for a car has a LOT more to do with living in NYC than your age or social status. You sound just like friends of mine from NYC.
Thus our (and my) psychological shift could be explained as simply as a preference for the hyper-connected urban lifestyle, with decreasing home and car ownership flowing from that change in preferences rather than a direct change in beliefs about cars or houses. Either way, the symptoms look set to persist.
Until you have kids, and you see how most urban school districts are run. This is the same reason our parents left the city and moved to the burbs. Things are not really as different now as we think.
Though now there is a huge opportunity to reduce the cost and drastically improve K12 education. If our generation can break the entrenched bureaucracy of public education, then I would say urbanization in the US could be more than a consequence of Gen Y being poor and delaying starting a family.
As soon as you even think about having kids, absolutely everything about how the suburbs are designed suddenly makes sense.
I still prefer an urban setting though.
The thing with age that young(er) people will never believe is that you change. It really doesn't matter what you think or believe now. It is unlikely to remain constant for 20 years.
Edit: last sentence was unclear
And wanting to not be reliant on a car is a big part of the reason I moved into the city in the first place. I did the calculation many years ago, and figured out that even from a purely financial perspective it's better - the rent's higher, but cars are impressively expensive to own, fuel, and maintain. And there are a bunch of other financial perks. Living within walking distance of numerous bars saves a mint in cab fares, for example. (Not to mention that suburban taxi service tends to be an enormous PITA.)
There may be a cultural factor to it as well. I don't find the need to drive everywhere like I did growing in the 90s, but I certainly don't have a ton of income left over for car and fuel (let alone even more debt for a mortgage and the other costs that entails).
My behavior is driven more by economics than culture.
MYSTERY SOLVED.
Of course you don't want to own a car in NYC.
I live in Toronto and don't want to own a car. We will need to get a replacement for our current car because there are enough things that we need to do that car services would not benefit us (we also live just outside of the core service area for every single one of the three—or is it four?—car services in Toronto).
This has nothing to do with economy, this is behavioral change. Freedom in all forms is the thing we value most of all and ready to spend a lot of money for, and houses and cars have negative value in this respect, they bind you.
This is not economically motivated - I have comfortable free cash flow and a healthy balance sheet free of personal debt. I pay for a car service and take taxis more than public transportation and pay more than the average U.S. homeowner's mortgage payment in rent. I also spend a great deal more than my parents, who find my behaviour and preferences baffling, on travel and technology.
I won't disagree that a significant fraction of decreasing home and car ownership may be explained by economic factors, but would caution that (a) there is a significant minority that is making these choices as a matter of preference, and, (b) for the rest, these behavioural changes, initially motivated by economic conditions, could become ingrained to where they persist beyond economic weakness. With the second point I'm not saying we will be a "cheap" generation, just cheap traditionally, as we spend in categories we value more than piles of sticks and little steel boxes propelled along asphalt by exploding chemicals.