According to the US census bureau (
http://quickfacts.census.gov/qfd/states/00000.html ), there were about 112,000,000 households in the US as of 2009. I don't know how many of these are in the top 100 metro areas, but it's got to be at least 70,000,000. So we're talking about 1% or less of all households affected by this public transportation "problem".
While it matters to the persons affected, in the overall scheme of things it's just not that big a deal. It's just a lot of hype.