I don't really want to wade into a political argument about health care, but this one specific part:
> The worst case scenario is bankruptcy, which sucks (though it sucks much less if you're already poor and have no credit to destroy).
Even though you immediately followed it with kind of a "but", I think you're seriously underestimating the effects of debt on someone in the U.S.
I have struggled financially for over a decade, after a period of doing really well. I could spend hours talking about the consequences of being poor (in U.S. terms).
1. Your housing options automatically become drastically limited. If you have bad credit, you don't get to pick and choose apartments or rental houses; you're more likely to end up in shared living arrangements or in the kind of apartment complexes that are willing to house people with bad credit, which also means your stuff is more likely to be stolen -- stuff that you can't afford to replace. (Having a load of laundry stolen was a hardship for me for about a year.)
2. Your employment options also become more limited. A lot of jobs, especially those that pay well, now do cursory background and credit checks as a proxy for judging whether or not you might try to rip them off. That of course makes it even harder to pay off your debt.
3. Forget about having reliable transportation. I've gone through 9 cars in less than 15 years: from one junker to the next. Used car prices are insane right now, so you're going to be stuck with someone's $500 or $1000 mechanic's special -- because that's all the cash you've managed to scrape together -- or you'll be doing a lot of walking and public transportation, neither of which are terribly convenient in most places in the U.S., which again limits your job options.
4. That beater you drive, if you drive one, becomes a target for law enforcement. They are most interested in cars that look like their registration may not be current, look like they may be a road hazard, look like they may be driven by a college kid with marijuana under the seat, look like they have a broken window ... the increased scrutiny is not only irritating, it can get expensive too, depending on just how poor you are.
5. Because your finances are limited by a lower-paying job, you're more likely to lack access to higher education, better quality food, or healthy hobbies.
6. You end up paying more for everything. You don't get to take advantage of discounts (for example, paying 12 months of insurance up-front), and if you do have any credit cards, you'll pay more on their rates.
7. If you don't have credit cards, every unexpected personal financial problem becomes a disaster. Oh, your radiator just blew a seam? Well, I guess you won't be driving anywhere for a while.
I'll stop there. Anyway, I don't completely disagree with you, but let's not just skip over the consequences of having a lot of debt. They can be really serious and long-term and dramatically change the quality of life someone has -- for the rest of their life.