And the article fails to mention a key benefit of self-drivers: removal of human error, and lowering of accident rates because of it. This is still theoretical, but it almost certain to become reality. Imagine saving 33% of the lives lost annually in car crashes. That's 10,000 people.
Another key benefit not mentioned is the enablement of non-empowered people. Sight-impaired people, young people, older people, people who are unwell or otherwise physically limited - all of these people can benefit from door-to-door service offered by self-driving cars, and not offered by buses. Yes, today there are "Access" vans, but cmon. Those are not a viable large-scale solution. Self-drivers will set many people free.
Self-driving cars are going to happen, because they're convenient and offer privacy and utility that a bus or train cannot. Some people will be willing to pay extra for that. Some won't. As the author of the article said: We need the mix.