Apparently the possibility that people might take advantage of the "no pre-existing condition" clause of the ACA to get insurance when something catastrophic happens disturbs the insurance companies' bottom line deeply.
This is precisely what's happening...it's called "adverse selection".
I personally know someone who switched plans during open enrollment to get a different carrier who would pay the $100k for her experimental treatment. She has to pay slightly higher premiums than the first plan she was on, but it's not a bad tradeoff when you're "buying" $100k of value for a few hundred a month. She can't be declined and her preexisting condition must be covered.
Everyone understands why you can't buy auto insurance coverage for a collision that already has happened. The same holds for health insurance—it's absolutely untenable otherwise. Not that there is any love lost between me and the scumbag health insurance industry. I'm just pointing out it literally actuarially/mathematically cannot work the way some people want it to. You simply can't let people wait until they have, say, cancer to sign up for insurance and then demand that insurance pay for the treatment.
What's the solution? Well, since we as a society have decided we do not want a free market in health care (a free market would necessarily entail leaving those who cannot pay to die outside the doors of the ER), then our next optimization is to save money. We spend more per capita and in total than every other nation, and we get worse average outcomes for our population.
To put it more plainly: a socialized medicine system like they have in the UK would COST LESS than what we have now.
Furthermore, the NHS public healthcare system in the UK works alongside a private, more "free market" type of healthcare system. We could mirror that here if we wanted to encourage the private industry innovation that appeals to our cultural sensibilities. We already have that in other realms: the USPS and FedEx operate side by side, there are private schools that operate alongside public schools, etc.
Finally, we need to realize that a huge percentage of the US population is ALREADY on socialized medicine (ie. governmental health care programs paid for by taxes): everyone who is over 65 (Medicare), the poor (Medicaid), the veterans (the VA), the Armed Forces (Tricare), all federal, state and local governmental employees (taxes pay their premiums). Does anyone believe we will ever elimated those programs, barring universal healthcare in this country? The "free market for healthcare" ship sailed a long time ago.
Let's just try to save some money and get better health for our population instead of trying to pretend a mathematically-broken insurance approach is ever going to be a good idea.