These claims have very little in common with the facts on the ground. A Google engineer can afford a condo five miles away in Sunnyvale ($700k), or a house ($1M) if they have a partner earning decent money too. These prices are absurd, and untenable for regular people who don't work in tech, but let us be realistic. Those are the prices because there are people paying them.
>A Google engineer can afford a condo five miles away in Sunnyvale ($700k)
If we're using the 2-2.5x income definition of "afford" that stands in the rest of the country, no. Total compensation across software engineers at Google looks to be about $160k [0]; a Googler can afford about $400k.
Not a lot of $400k condos around here.
To get to $700k, you'd need a married pair of Googlers (not an easy thing to do in this overwhelmingly male industry), the equity from a paid-off house somewhere else in (more likely), or the willingness (and lenders' willingness) to spend a much higher multiple of your income (seems to be what's happening).
I'm not sure the average Google software engineer according to Glassdoor is representative enough of Google software engineers who would be buying housing that it's valid basis to make assertions about housing affordability.
It's extraordinarily unaffordable in the Bay Area and none of my friends there (at Google, Facebook, or elsewhere) would say it's easy, but I don't think $400k is the right number to pick even if you're conservative about affordability.
Google has been hiring extremely heavily over the last 4-5 years, and their HQ gets tons of early 20s fresh university hires. So I'd expect that $160k number (which I see as $166k?) to be skewed down a bit. Anyway, fresh early 20s university hires aren't likely to have the savings, stability of personal situation, or desire to buy property.
You're probably looking at more established engineers as buyers, and they'll have been able to save longer and advance in their careers, and $160k + the standard 20% down payment is probably on the low side for that.
Glassdoor's numbers don't change much when you bump up the experience, and I'm afraid I don't have sources other than my fairly extensive social network at large Bay Area tech companies, but I can pretty confidently say 3-6 years out of school that yearly total comp number will be $200k+ and if you're saving properly without 6 figures of debt you'll have upper 5/lower 6 figures saved to put down on a place.
$700k is still a stretch, so I think your point still stands, but I don't think you need to be a dual-income Google/Facebook/etc. software engineer household to afford it.