Right but the ability of you and many Americans to live in such low-density areas is fully supported by the massive amount of resources directed towards car-centric infrastructure. The problem you refer to- that public transit cannot service low density- is one which creates itself. Moreover, low-density means low tax revenue and infra is EXPENSIVE; more expensive in many cases than the low-density tax base can support. The net result is that revenue to build infra is generated in high-density areas and then spent on low-density ones, which weakens the public transit offerings in high-density areas and encourages more driving, which encourages more low-density living, and the cycle continues. This is not sustainable, and something will give eventually.