What happened?
Certainly, it's pro-growth (for AirBNB), but I don't see how it's pro-housing for anyone else. Unless you expect to live week to week in AirBNB rentals.
Small potatoes, but still in the "maybe we should build more housing" direction, so, tasty potatoes.
The situation on the ground is... substantially more interesting than you make it out to be. You should really read this partial analysis of the existing short-term rental regulation and the changed proposed by Prop F: https://www.jwz.org/blog/2015/10/yes-on-f/#comment-164412 Edit: NOTE. You'll need to copy and paste the link, rather than clicking on it. HN triggers JWZ's anti-hotlinking code.
If anything in the prose is unclear, feel free to ask questions.