Those people who live in those neighborhoods probably don't have college degrees and tens of thousands of dollars of specialized training. I'm willing to bet that they would not continue to live in those neighborhoods if they obtained the above education. Aside from that, I do agree that $40k is enough money to live in most areas of this country. The contention is not that we are underpaid relative to the median household income in the country, its that we are underpaid for the level of investment in our skill set.