Here we go again, concluding we shouldn't buy houses because we won't make money from it.
Personally, renting is better value than buying for me, even given london house prices.
The article is saying that from an investment perspective it doesn't make sense to buy a house in SF right now if you work in tech.
It's not saying you shouldn't in general. If you derive a ton of value from buying a house, buy a house, just understand the risks of doing it, and buy less house so that if it goes down and you lose your tech job, it's not ruinous.
It's true that everyone needs somewhere to live, and I really, sincerely think that public land should act as a fallback. Currently, the fallback is jail, and that isn't working.