That's because the article is pretty much boilerplate. It's the same hackneyed arguments that's always trotted out with no attempt to actually analyze the very real problems in San Francisco and the surrounding area.

Cases in point: The author blames two classic boogeymen: control and tenant protection laws. As you pointed out, rent control simply doesn't apply here. As far as tenant protection laws scaring off landlords, even that doesn't hold up to even the most cursory analysis. As the meme says, "The Rent is too damn high." If landlords were really holding apartments vacant at sizable rate, the rents would increase even higher and The Market(tm) would simply bring the vacant apartments online because the expected value of the apartment would simply be too great to ignore. Finally, if you follow the link that says "thousands of units are simply being kept off the market", you find out that the unit in question is actually rented to family instead of perfect strangers. Which is to say, the unit isn't vacant.