I think it depends on where one lives. Yes, those three cities may be faster; however should someone live IN Oakland, it may take them mere minutes using public transportation to get to the Oakland airport.
And, using Oakland as an example, it takes me less time to get to the Oakland airport from my house using public transport than it would if I were to take my car simply because of traffic.
However, to travel to my home to San Francisco (SFO) it is actually longer to take public transport due to how the BART lines are set up. But, knowing me, the one time I were to drive to SFO would be the one of those times that there is a huge big rig jackknifed on 101 causing havoc in the Peninusla region of SF Bay. So, I take BART.