Most people who do this (taking the car) realize that (if we all take the bus, it would be a pretty smooth ride) - but first of all not all people CAN take the bus (mostly those coming from further away) and second, I can't fault them. If your commute is like 30mins by bus and 15mins by car... easy choice for ~22 days per month
A 30 minute bus commute sounds very optimistic. BART is the only system that has ever made me confident I won't waste 30 minutes before even being picked up.
