Not everyone lives 3 minutes from a Metro stop!
Even a 20 minute drive to Metro is better than 45 minutes stuck in gridlock.
Uh huh. 20 minutes to the metro, 5 looking for parking, 15 waiting for a train. Then the train ride itself with the nice chance of standing the entire way, listening to some idiot babble on a cell phone, or shriek to their friends about American idol. Then a what, 5 to ??? walk to my destination? No thanks.
Then there's parking. By the time you get to the metro, wait for the next metro going your way, get to your destination stop, and get to your job, you've just chunked more than 45 minutes out of your day.