40K of folks who can afford to pay the rent, without having 20 stuffed in the home and garage, leaving was just the beginning. It’s just like slowing sales and home prices; just give it time, and the cumulative reduced demand from the folks-who-can-pay leaving for AZ, TX, and ID will result in reduced prices.
The rental prices you cite for Clairemont and La Jolla include 1BR and 2BR apartments and condos. There are few 4BR apartments, so I use the 4BR rate ($2,184 for Clairemont, yielding an 88% premium for La Jolla), as it reflects rental prices for homes, not apartments.
San Diego is a great place, but at these prices, it makes no economic sense for a business. If all one needed to attract and keep great researchers was ocean views and cool breezes, Nice, FR and Naples, IT wouldn’t be the economically depressed places that they are. General prices are too high here, and must fall, or else only retirees and their Mexican housekeepers and gardeners will remain, ’cause rational businessmen like me will leave.