Because while you wait for housing to be built there is currently a housing shortage, and existing houses are being used as short term rentals. And you're assuming developers will act in good faith and not just use multiple floors as short term rentals which already happens. I'm all for building more housing and saying fuck short term Air B&B's. There's no reason we can't do both.

I live in a place that is plagued by short term rentals. It sucks for the neighbors to have a different bachelorette parties next door every week of the summer. Lime scooters get littered all over the sidewalks in front of said houses. And we've already voted to ban them in residential areas but there is 0 enforcement.