Remember: Any time you hear an employer whining about "lack of qualified candidates" be sure to mentally append "...at the rate we want to pay."
But if the cost of an employee is > their value, you get massive off-shoring. That's the danger, and as an Australian the opportunity, of Bay Area pricing being so crazy.
If the Bay Area wants to keep its advantage - in a world where Alibaba is the lead IPO of the last 5 years - it needs to remain competitive in all ways.
Rome wasn't built in a day, but it fell in one.
It may be that the cost to attract talent to the Bay area is now too high for all but the most profitable businesses. I have no idea if this is true or not but conceptually the giant payrolls needed may finally be overwhelming the benefits of locating a company in the area.