This is the type of unserious, policy-by-press release we've come to expect from the micromanagers in the U.S. Congress.
First of all, housing is still overpriced, in terms of historic trends, in many markets.
Second, this is yet another program for ICE, which cannot manage its current immigration visa portfolio. This idea seems particularly open to abuse, since the home could be bought with borrowed money. (Sure it has to be "cash" investment but there's an asset here, you could easily cash out or have straw buyers.)
I wish these guys would come up with better solutions to the banking crisis (yes, it isn't over) than selling U.S. visas.