Presumably you're defending this point of view. I'll assume you haven't thought about it.
The reason insurance companies charge premiums is to cover their risk in the eventual case expensive care is required. You pay while you don't need it so that you can receive care when you need it. Now, if you isolate the "sick" in a pool, there is no reason for insurance. Alternatively, this could be looked at as a way to grossly enrich insurance companies by letting them collect money from healthy people but transfer the hard work (paying out claims for the sick) to the taxpayer. Either way, this is an argument for single payer.
It would, in addition, do absolutely nothing to contain costs. The taxpayer becomes responsible for both their own health insurance as well as the government-sponsored "sick pool." Given the inefficiency of the government, it's likely that costs to the end user would increase substantially. At the absolute theoretical best, they would remain the same, but then that would obviate the need for such a program.
Any amount of logical thought shows that this is an argument for single payer somebody with the rationalization ability of a high school sophomore would propose.
If I were you I wouldn't be scolding others about "sophomoric thinking," until you can pull the old plank out of your own eye first.
To begin with, you're talking about health insurance as if it were the same sort of beast as car or life insurance, in which premiums and coverage are predicated primarily on risk; and we're expected to pay those premiums ourselves.
But that's not how health insurance works, for most of us, and it hasn't done for a long time. What we call "health insurance" is probably better described as a form of cost sharing, and the majority of the costs are borne not by individuals, but by employers. There's certainly a risk component involved in the pricing, but the risk is handled much differently than it is for something like life insurance.
Moreover, for pretty much everybody, "health insurance" ends at age 65, at which point Medicare coverage begins, and the taxpayers already have that burden. (It's also where most of the health care costs are carried, I suspect.)
You're also skipping over Kudlow's key point: the fact that those 5% account for 50% of health care costs. That's probably a correct statistic. At any rate, that 50% number is something that bears serious scrutiny: is it possible to find a way to remove that cost from the cost pool of the relatively healthy?
Just suppose that the insurance companies did not have to deal with that "sick 5%." They'd be looking at a significant reduction in outlays -- probably not 50% less, but a lot less. This could (as your interestingly Bernie Sanders-ish argument goes) "grossly enrich insurance companies," but that's where your argument becomes sophomoric.
You neglect to address the fact that employers negotiate their premiums with those same insurance companies, and have a very strong vested interest in reducing the premiums
they have to pay. It would be very strange indeed if insurance premiums did not go down.
So we're left with the remaining 5% of the people. The question is: what does one do about that 5%? We cannot expect such people to be able to shoulder that sort of cost. So do we let them die, or do we help them to find some level of treatment? If the latter, how is it best done?