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Because I do not have faith in private charities as a long-term solution.
Private charity is far more sustainable in the long term than any government-operated health care plan. The Federal government currently operates two health care programs - Medicare and the VA. Medicare is currently about $70 TRILLION underfunded. It is bankrupt several times over and the unavoidable result will be that the promises of benefits that were made WILL be broken. This is long-term solution government style.
Putting aside the VA's reputation for low-quality of service, the cost alone makes it unworkable. For the most part, the only vets who use the VA are those who have no other choice. But ignoring that for the moment and assuming that all eligible vets use the VA for all their healthcare services, if you extrapolate the cost per covered person to the entire nation, the cost of VA care would be around $2 trillion annually. For marginal care. And that is an extremely conservative estimate. How would you possibly pay for that?
Or is there some reason to believe that the Federal government's unbroken track record of failure in healthcare (and most everything else) will somehow be broken if we just make the program big enough? I would be interested to hear it.
But you might spend your time more profitably trying to understand how government has created the huge problem we now have with healthcare. Hint: the high cost of health care results from restrictions on supply and subsidy of demand.
Because charity is voluntary and costs the consumer more than it benefits them, it presents a free rider problem.
And yet Americans have a history of giving generously to charity - even while the government is siphoning off vast amounts of wealth and wasting it on war etc. Could it be that giving to charity has a benefit that does not show up in your cost/benefit analysis?
What would happen if society becomes largely amoral or Randian (not to link the two)?
It really is a bit misleading to talk about "society" wanting this or that. Only individuals have morality and intention. But for the sake of responding to your question, which is a legitimate one, what would happen if society became "amoral" is that society would have exactly as much charity as it wanted. If society no longer cared about the poor then the poor would not be cared for. Of course you personally would be free to sacrifice yourself for the poor to your heart's content. But your concern is that other people would not share your morals. Unfortunately your solution of using violence to force everyone else to act on YOUR morals is itself morally depraved.
Who would provide care for the impoverished people then?
You, and me, and anyone else who cared or felt guilty or could, with your eloquent pursuasion, be made to care or feel guilty. And it would be enough even if it was less than you thought appropriate because YOUR values have no authority beyond your life. There is no justification for you, or me, or anyone else, to deem their values MORE VALID than the values of anyone else such that our values can be imposed by force.
Besides, government doesn't help the poor. Government nurtures poverty to perpetuate and expand its own power. Understand the difference?
Oh, and here is the bonus question: who profits from the food stamp program ostensibly designed to "help the poor"? Hint: someone gets paid to administer the program.