I agree that the core problem of housing affordability is that housing serves a dual role as an investment and a place to live. But I think this policy will not do very much and in isolation would even be counterproductive.

Why focus on single family homes? If corporate ownership is as bad as you are framing it then why is it OK for someone who lives in an apartment to be advantage of? Worse still, these entities would still want to invest in real estate so presumably they would invest even more in multi-family properties. If their ownership is what causes unaffordability, are you not making things even worse for people who live in multi-family housing?