The issue with your suggestion is that you're presuming that this guy can keep building more buildings, but he sold his company to be able to do this. It's a one-time deal, unless if he manages to start another company, raise it to a great value, then sell it off again. Even then, that's a decade venture at least. Planning as well doesn't take that long, it's the approval process that does. Planning can be over with in less than a month, and that's presuming he doesn't go for an existing plan.

There are always people on the verge of destitution, so either save a handful today, or save several times that many a year or two later. Low and mid-rise apartments are not only massively space efficient, but cost only a fraction to build compared to a hundred individual homes, as the single building shares many of the same components for all the units. Not only does it use less parts, but the amount of labour is only a fraction of so many houses.