It depends on the suburb. I could see myself living in someplace like Manayunk without car, but I suppose that is sort of pushing the meaning of "suburb". Some of the towns along the Main Line seem fairly livable without a car (For a time I did the opposite, living in Philadelphia and working in Radnor), but that doesn't seem ideal. Some of the other towns along the Main Line are definitely as he describes.

I whole-heartedly agree that it is highly dependent upon the burb. Something as simple as a grocer and a hardware store in a town center can make a world of difference.

Transportation alternates are also highly variable and make a huge difference.