Ask HN: What are the implications of Senate Bill 593?

http://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=201520160SB593

I got an email from Airbnb asking me to email the CA state senators to oppose SB 593. I'm not entirely sure if it's a good or bad thing. Any explanation as to what the long term implications of this could be would be super appreciated.