No talking points, please. I am trying to understand why it was deemed necessary....Please be specific. Thank you.
You are really asking three questions:
1. Why do anything about health care financing?
2. Why do the ACA framework instead of something else?
3. Why do something now?
Here are my answers.
Why do anything about health care financing?
Our present health care financing system is collapsing. The percentage of the population covered by health insurance falls 1% a year, health insurance costs are a major and unsustainable portion of the cost structure of many industries, medical costs are the largest cause of bankruptcies, and we pay double what any other developed economy does for health care for mediocre results at best. So the alternative is to watch the system collapse, with medical care becoming more expensive and less available each year, our public health statistics and death rates worsening, and our economy pulled down by the dead weight loss of the failed health care financing system. That's the case to do something. Not everyone finds it compelling.
Why do the ACA framework instead of something else?
At the beginning of the Clinton administration two decades ago the Republicans successfully fought off a proposal for health care financing reform, pointing to "flaws" in the proposal and promising to come back with their own proposal next year. Note that this admitted that something should be done; they did not try to convince America that doing nothing was a good option. Of course they never did put forward a proposal. But they did generate a framework from the Heritage Foundation for a private market-based solution instead of the two competing models (single-payer/private supplier aka "the Swiss model" or "Medicare for all"; and national health care on the British system aka "socialized medicine" or "VA for all"). This is the structure implemented in Massachusetts as Romneycare. The ACA IS the alternative Newt promised to produce in 1994.
Personally I think single payer is a better solution because ACA has no real effective cost controls. We got the ACA because it was what the hospital chains, big Pharma, the medical device industry and Congress could be talked into. Anyone who says at this point that we should ditch the ACA and hold out for "something better" is just playing Newt's game, as there is no other proposal out there except for single-payer, which is less acceptable to big business and conservatives than the ACA.
De facto, the something else, is to just watch the system collapse.
Why do something now?
I suppose we could put the whole thing off again, but that doesn't solve the problems. Personally I think the present system imposes an escalating damage to American society and the American economy that is permanent and will reduce us further to the status of a barbaric medieval society, on a par with third-world countries. Some people look forward to such an outcome; it concentrates power in the hands of a few and makes everyone else desperate for protection, but it definitely is not my view of a successful future. It's a fascist dystopia, like Chile under Pinochet.
To your specifics.
It seems to me that there are three existing groups of people with respect to health insurance: People who have it, (young) people who didn't want/need it, and people who can't afford it. The last group can receive health care through Medicaid, but they have to exhaust their resources first.
Actually millions of uninsured Americans do not qualify for Medicaid or other government assistance and cannot afford private health insurance. Most of these work. There is a lot of data on this and most people see these people every day in ordinary life. Your caveat above admits the situation, but your premise that a system that requires impoverishment of workers as a condition of obtaining medical care iw what shocks the rest of the world which views medical care as a basic human right.
No. Medicaid is the most efficient method of delivering health care in the United States today, far superior to Medicare which is the most popular. The runner-up is the socialized medicine component, the VA and military health systems where the government builds and owns the facilities and hires the personnel. Obamacare is a step back on cost containment, which is its major weak point.
If so, is simply shifting this burden to people who don't want/need health insurance really a legitimate way to do it? Aren't there other ways to do this (e.g., tort reform)?
Technically since the preceding answer is no, this is moot. But yes, there are ways to contain costs and we need to look at them, especially as the ACA will probably need some tinkering to achieve reasonable cost controls. I see absolutely zero conservative proposals for controlling medical costs short of the famous "Let them die!" response in the presidential primary debates. That's the level of discourse on the Right. If this sounds like "talking points", it is only because you are phrasing issues with loaded assumptions, the talking points of the Reactionary Right, and I chose to call you out on it. You don't make rules you violate in the OP and expect to not get called out on it do you?
If not, what was the purpose? Was it to lessen the stigma of receiving government assistance and/or to promote Social Justice (e.g., "voluntary" affirmative action programs by "approved" health care providers)?
No, the purpose was to save the economy, make it more internationally competitive by taking medical costs out of unit labor costs and improving worker productivity, improve access to health care and reduce mortality and morbidity rates in America, and start to control health care and health care financing costs better. If you want to discuss how any of these results can be reasonably expected to flow from the ACA, I will be happy to oblige. Just don't answer everything with "talking points".