You're being sarcastic but it's actually true, per Triumph of the City (http://www.amazon.com/Triumph-City-Greatest-Invention-Health...)
SF has certainly encountered the diminishing returns of limiting the number of people. The city has adopted policies that prevent growth that make it impossible to invest in those features of cities that increase the returns. Transportation is far worse than it could be and its impossible to justify investments in upgrades and improvements, because the city won't experience the growth to justify making those investments in the first place, and the current tax base (and land tax policies) is inadequate to fund those investments.
I've lived in three cities that have gotten worse over the time I lived there as the population grew and all the problems were the result of policies, not more people. Those cities are São Paulo, Beijing and San Francisco. The main thing all three cities have in common is an existing populace of extremely selfish people not only unwilling to give up their cars, but demanding more car conveniences. It's a classic tragedy of the commons issue.
Heck, even my gf, who didn't have a car when we met, tries to justify her car ownership ("it's a smart car" or "I share it via getaround and city car share"). The attitude of entitlement and "but my car usage is an exception" is the reason SF is getting shittier, not better.
I myself have been hit by cars twice cycling in the bay area and I'm recognized as a much better cyclist than most of my peers. If that happens to me, it becomes easy to understand why many people I know find SF to be too dangerous to bike in, especially during the work week.
I'm slowing reaching the point where I greatly resent that the core of the tech industry I want to be part off has chosen such an ass backwards city full of people who try to be progressive with respect to the policies of the rest of world, but are too selfish to be progressive here at home.
THIS. It's everywhere, you know. You just have to look for it.
Isn't it possible, though, that if nice, enlightened liberals, in their characteristic broad-mindedness, are choosing to restrict population density when it's good for them, that restricting population density (at some threshold, at least, if not necessarily theirs) might have something to recommend it?
Or, maybe not. Maybe we can safely just call them hypocrites and be done with thinking about it. I dunno.