Since when is homeownership a requirement for retirement savings? What about IRA's, 401ks? That they chose to stake so much on a more volatile asset is not the fault of the people around them. Should cities sacrifice their urban well-being, pushing people out on the streets and guaranteeing lower-income people can never live there, for the sake of some elderly residents who put their eggs in one basket?
No, it's not. In 2008 we saw that that is really not the case. Housing is awful because it's relatively difficult to find an owner and transaction fees are extremely high.