Traditionally the guideline was that housing costs (rent, utilities, etc) shouldn't be above 30% of gross income. $66K / $300K is only 22%. So, I wouldn't call it insane.
$1.5m is a much more realistic sale price for a modest home in a good area, and with 20% down that’s more like $10k a month between mortgage and taxes and insurance.
It's SoCal - Torrance CA specifically as mentioned in the article. Prices are slightly lower because salaries are slightly lower (or maybe it's the other way around)
Median detached home sale price in Torrance is 1.275m. The $900k figure probably includes condos and is not what a house costs.
https://www.redfin.com/city/20094/CA/Torrance/housing-market