That is a very good insight. One of my teachers shared a similar insight at school when she told us that she wasn't going to be at school for the last two
class periods. I don't remember the exact quote, so I'm paraphrasing:
Medical services are one of the few institutions that can hold people hostage and make them wait an inordinate amount of time to get stuff done because there just aren't
enough of them. Most people would not put up with waiting five days to a week to just place an order at a restaurant, but you have if you want that doctor's appointment.
Likewise, as you noted, mechanics can hold people hostage by their funky time schedules, too.
I'm not sure if this is related, and it would probably be better discussed in the
Politics or Ethics subforums, but I think there might be a correlation between the way American healthcare is handled and doctors trying to "oversell" services.