Historically, San Diego has always scored low in job creation–even at that–it’s better than it used to be. Probably why so many people who grew up here end up having to leave to make their degrees pay off.
With the exception of the Bay Area cities, most of the cities that ranked highest with regard to job creation have a lower cost-of-living and are far more “business friendly”–issues which have long been discussed as barriers to growth here.
Personally, I don’t see those things changing much in the future, but, finding ways to effectively address those issues might provide a starting point for change.