Two objections, one factual and one more philosophical. First, it's actually not true that most major U.S. cities are bereft of single-family homes. It's the dominant form of zoning. See here: https://www.nytimes.com/interactive/2019/06/18/upshot/cities...

But, second, any objection that places the blame on "greedy landlords" is a total nonstarter. Everybody is responding to their incentives. Landlords aren't greedier than anybody else. If widget makers could set higher prices, they would. They don't because they can't, not because they're "less greedy."