Seems to me it's a false equivalency seeing how one choice puts you "in the city", and the other has you living way the hell out by the airport. Next up, is "living" in the Midwest cheaper than renting in the city of San Francisco? Silly, I know, but the article itself just comes off as space-filling fluff, or at best an interesting thought experiment.
Anecdotal counter-point: my 3 friends and I split a spacious, sunny 4-bed in the mission for $6,000. So $1,500/person for a private room 15 minutes (by bicycle) from SoMa. The 'SF is so expensive that you should just live at-the-airport/in-vegas/on-the-moon and commute' argument is a bit overblown at this point.