There's certainly an argument to be made that such freedom benefits all but the poorest (those who neither travel nor own real estate), but is restricting this

There's certainly an argument to be made that such freedom benefits all but the poorest (those who neither travel nor own real estate), but is restricting this convenient, popular, voluntary service a reasonable way to approach the much broader income inequality problems? That's a stretch. Seems to me like it's a natural consequence of a more connected world, and like you mentioned in another comment, there are more significant issues such as zoning and nimbyism that should be ground-zero for real estate prices in most cities. In fact, I'd go so far as to say that Airbnb increases equality by democratizing travel for the lower middle class in a way that was inaccessible before, at the biggest expense to hotel owners. I'd also like to see numbers on real estate usage in NY (defined as the percentage of each unit occupied per unit time) before and after Airbnb -- I would wager that living quarters are being used more efficiently as a result. And of course how much people travel now vs. before (which I think could be considered a quality-of-life metric).