It takes what would otherwise be rental units for SF residents off the market and instead provides them to tourists. So my opinion is that yeah, that hurts the residents of the city.

You could make the argument that increasing tourism, or increasing the available footprint of where tourists stay (ie not just downtown where all the hotels are) is beneficial. I would actually love to see legit bed and breakfasts open in many more parts of the city. As it is your hotel choices are basically limited to downtown and Fisherman's Wharf. But I don't think helping tourism in SF should come at the cost of making the city less affordable for residents.

Yes. It reduces supply in the long-term housing market by taking a unit that otherwise be permanently occupied and renting it out short-term. I like staying in STR's when I travel, but I think this is a case where some regulation is reasonable. Hotel rates are so much higher than long-term rental rates on a nightly basis that there's a strong market incentive to use your property as an STR rather than LTR.