In my imaginary property model, the VCs make money regardless of whether the companies they back succeed, while the investors only win 1 out of 7 times, upon company successful exit. To the investors, it _looks_ like they've put a lot of money in the startups, but a significant portion of that goes back to property rental companies via salaries and office rentals. Which would be lower anywhere else, which is why I suspect the VCs are disincentivized to move companies elsewhere (or invest elsewhere). They make the most rent here.
But I don't actually know anything factual, like how many VC people privately hold heavy investments in bay area REITs. Even a well-intentioned (dedicated to making their client companies successful) VC would be a fool to not invest in REITs, now that the cycle is here, but after a few years of that and seeing where their money really comes from, I wonder if they can keep their good intentions.