Not homeowners, short-term rental investors. Many probably are homeowners, but that's not relevant - many more homeowners saw absolutely no change, since they didn't invest into this particular industry.
> Eliminating thousands more rental units of coming onto the market
Thousands more short-term rental units, not real rental units. People who renovate/build for AirBnB will keep their units on AirBnB, not suddenly decide to put them up for real/long-term rental. The units that theoreticallt won't be built now wouldn't have helped the housing crisis even a little bit.
Without regulatory intervention, tourism is so much more profitable, that anyone who wants to invest in realestate and optimise for profit would be foolish to deal in long-term rentals. By making the AirBnB business model less profitable, some investors might actually go "back" to investing in long-term rentals, increasing supply.