Who is asking them to? The US has an enormous supply of such housing, after decades of restrictive zoning codes which make it difficult to build much of anything else. Some fraction of the US population live in single-family detached suburban-style homes not because they value those features but because that was all they could find. People who might prefer city living often can't have it, because the old forms of development which used to cover the spectrum between the single-family detached house and the downtown high-rise have generally been banned.

In order to solve the housing crisis, we must fix the zoning codes to allow a much greater variety of development patterns, allowing gradual small-scale infill. Nobody is going to stop building single-family detached housing so long as there is a demand for it - but relaxing the zoning codes would mean that the existing, unmet demand for other types of housing could also be satisfied.