So, in other words, they bought a house that they could only afford if they didn't have kids and now are using its value to renig on their promise to pay. Also, isn't it "special" that they can afford to make the payment, but have decided not to since last summer, while continuing to live in the house. What honorable folk.
CRA created this originally. Now Government regulation of mortgage lenders (difficulty of obtaining a mortgage) is guaranteeing that values will remain suppressed.
Under these circumstances, I don't blame people who want to walk away.