I’m not sure that we fundamentally disagree, though from these samples I don’t know enough about your position to be sure.
When you say, “you need to think bigger than that. In fact, we need changes all the way up to the federal level,” I agree. The government up to the federal level has been using policies, tax benefits, and direct subsidies to promote detached single-family homes. I think that your solution of reorienting building priorities in favor of individual housing is not incompatible with my idea of removing homes as a long-term investment. Indeed, I think they are aligned: The most economical way to live by yourself is to live in an apartment with a whole lot of other people.
The suburban ideal has cost the country tremendously. Roads, sewers, air pollution, mental disturbance from the isolation, extended emergency vehicle response times, to name a few aspects that come to mind right now. Even perma-camping would destroy the environment if everybody did it. If we want to reduce our per-capita environmental impact, we are going to have to live in dense apartments, and we are going to have to make them affordable for everybody.
For cities to be affordable, we need to overrule the NIMBYs and allow the housing prices to go back down.
Where I’m least sure I agree is with the primacy of single living. A good solution will involve a diversity of housing stock, and we do need more single housing, but any society who want to survive long-term must encourage people to breed and produce a next generation. And once you’re done breeding, outcomes tend to be better if you’re involved with the next generation’s progeny, too. For the long-term health of society, we need plenty of large houses.