Right, so if there is similarly an artificial shortage of housing as the comment I responded to suggests, what's the fundamental reason the problem couldn't be solved by technology (e.g AirBNB)
If you lived in NYC, you wouldn't see Airbnb as a solution but rather a problem created. It allows transients into buildings and we don't want that. We value our safety and pay for it financially.
The real solution is to undo the laws that create the artificial "economic rents" that benefit landlords at the expense of renters. See Economist Glaeser's column I cited above.
You can't really skirt regulation in the same way when it comes to building housing. People are going to notice when you try to erect a 50 floor skyscraper in a historical district.
If you want to increase the number of residences on a given piece of land, you have to replace single family homes with high-rises, no way around it.