I would say the number for whom driving is a passion is a significantly smaller number than those who drive because they have to.
That said, the quote I thought was interesting, from the summary:
Buying sexy, fast cars for garages could evolve into buying seat-miles in appliance-like pods, piloted by robots, parked in public stalls.
This is an intriguing point. What you might end up seeing is the death of economy car.
I have a fast and sexy car in my garage (okay, it's not THAT fast but it is kind of sexy, or so I've been told). One reason I bought it is that I liked how it looked, it had decent performance, was comfortable, and still got good gas mileage. But I'll be the first to agree that, at least out here in Southern California, what kind of car you drive generates a certain image about you. And I'm not sure that renting a self-driving "pod" for a date would give the same message as showing in a gorgeous Mercedes, Bentley, or Maserati.
Those who buy a Toyota or Honda because they're solid, dependable, economical cars would be the first people to trade in their cars for a rental pods. But the people who buy "aspirational" brands--Lexus, Cadillac, Mercedes, etc.--wouldn't be so quick to trade these in because they'd be giving themselves a poorer image. Arguably, if I pull up in front of a club in a self-driving rental "pod" versus pulling up in front of a club in self-driving Mercedes or a non-self-driving Lamborghini, I'm getting a heck of a lot less attention from potential sexual partners.
The mistake, of course, is to think that it must be one or the other. The reality is that, here in America, there is room for all of them. Like I said, I could see people who live in dense urban areas renting a nondescript pod for a trip to the grocery store where it would be inconvenient to carry all the groceries home in your arms. I could also see people owning their own slightly nicer pods because it's more convenient to go out to the garage and hop in every morning and be able to leave stuff in your pod. Heck, you might even defer some of the cost by renting out your slightly nicer pod when you're not using it. You might see luxury pods with bars and hot tubs.
You might even see non-self-driving cars! Like you said, I think there will continue to be demand from those who like to drive and those who don't feel comfortable entrusting someone/something else to transport them. What I think will be interesting is what form those cars will take? I mean, a self-driving sports car would be like a Harley with training-wheels. But sports cars can be expensive. Would it be worth it to produce inexpensive sports cars--like Kias? Are there enough people who would buy these to drive? Or will it become only the province of the wealthy to be able to drive themselves?