Small children
and 2 weeks of groceries for a family of 4-5? For 10ish miles one way? On the low end?
The healthcare point is because it means that a lot of elderly Americans have medical conditions that are unattended to, injuries that never healed properly, etc. It's common, particularly in the working class, to have your body be functionally wrecked by the time you're 55 (particularly for men). If we want the elderly to be active, we need the infrastructure to allow that rather than declaring that any health condition that won't kill you in the next two weeks is fine for the poor to deal with, actually. Heart conditions are really common, diabetes, COPD, poorly healed injuries for those who at one time worked blue collar professions, etc. Someone who lost their foot to diabetes isn't going to be cycling and sure, if they'd been more active 30 years ago that might not have happened, but it's the reality now.
I support public transit and biking infrastructure and totally agree it's great for disabled people as well - one thing I found interesting when I lived in a city with decent transit + universal healthcare is how many more physically disabled/elderly people I saw out and about going about their business.
I just find that the idea that we can just get rid of cars/that everybody who uses them just doesn't know any better overlooks a substantial amount of the population and their needs, and you need to address the needs first if you actually want to move away from the car. It has big 'everybody is a single, able bodied 25 year old man without dependents who lives in CA or the PNW' energy to assume those of us in cars are just not educated enough to know better. Like now even when I travel I don't like taking public transit because I'm immunocompromised and being jammed in with that many people is a health hazard. I'm not stupid. Neither is the exhausted mom with 2-3 kids and one hour to get across town to buy food for the week.