The New Housing Supply Fund is designed to increase the availability of affordable housing by providing funding to support the construction and development of new homes. There are a lot of philosophical reasons someone might argue for ending this – opposition to public housing in general, reducing government spending, et al. Carson may even believe that private home developers will step in and provide affordable housing if we reduce government intervention (I’ll leave it to you to decide how likely you believe that one is.)
The bottom line, however, is that this would cause a reduction in the affordable housing supply, particularly for low-income households and vulnerable populations. This would lead directly to increased homelessness, higher housing costs, and higher rent. If we make it more difficult for people to find affordable housing, we’re widening the gap between the rich and the poor even further.
Full contextual analysis of Section 3.6: Department of Housing and Urban Development here.