Increasing the number of housing units doesn't solve the problem though. What is to stop people with money from buying those up and then Airbnbing them out?
Those "landlords/property investors" have enough cashflow and collateral to continue to expand their portfolios and get lines of credit to do so, which puts 'normal people' looking for housing at a disadvantage.
In high-demand housing areas, there needs to be more housing regulation to balance the businesses vs. individuals. It's good that there are cool places that encourage visitors to temporarily stay and spend locally, but there are also people wanting to live there that would also spend locally. The property businesses are making such a $/day killing on Airbnbs that they would rather keep that system than rent units for people to live there (and have to adhere to all the landlord laws).
Airbnb is a convenient loophole that offers more money with less effort as long as demand is high.