I'd say that both are generating value. The people who buy building and rent out all the rooms or Airbnb provide a liquidity the market needs - they are doing

I'd say that both are generating value. The people who buy building and rent out all the rooms or Airbnb provide a liquidity the market needs - they are doing something "of value" If they do that for profit, odds are they are making money and the next best use of these buildings would bring less money.