You know the old saying: "It is better to travel hopefully than to arrive"? Well, that's literally true when you're dining out in San Francisco and relying on taxi service. Forget about the cab being on time, most of the time you just hope it shows up at all.
My husband and I MUNI'd for a few years, but door-to-door, the travel time was sometimes over an hour when the restaurant was only ten minutes away by car. We have our own car, but parking is a nightmare in some neighborhoods and we enjoy wine with dinner. There are enough drunk drivers careering around the streets of San Francisco, we don't need to add to them.
Correct me if I'm wrong, but when you call a cab company and they tell you they're sending a cab your way, you've entered into an agreement. They've agreed to send you something, and you've agreed to wait. And wait. And wait. AND WAIT!
It's gotten so bad that after we call a cab, we now look at the clock and estimate how long we'll wait before we try to hail one off the street or call another company.