It's not so much about it being Asian, but the Outer Sunset is about as far away you can get from "the action" and still be in San Francisco. Also, it's colder and foggier than points east.
Outer Sunset is right next to Ocean Beach [1]. It isn't that bad if you can tolerate the fog, and daytime temperatures in May-Sept will frequently be in the 12-16 C range. And it's only 20-30 min from the downtown hotspots, and maybe 60 mins drive to Sandhill Road (traffic permitting).
The real saving the author is getting is on rent, the Asian food shops, etc, are not that much cheaper than Walmart, but much more tasty.
https://www.google.com/maps/place/Outer+Sunset,+San+Francisc...