Unlimited cost of care under the ACA health insurance policies?

In The Des Moines Regiser’s report about Wellmark getting out of the health insurance market for individual policies under the Affordable Care Act (ACA), they reported, “Forsythe (CEO of Wellmark) cited a single Wellmark customer who has a rare genetic disease that is costing more than $1 million per month to treat.” One person – A million dollars a month.  (See link to article below.)
One of the fatal provision of the ACA is the requirement that there be no limit in health insurance policies on how much can be paid for any individual’s care. No limit. Should we really expect others (society) to pay a million dollars a month for the care of ourselves or our family members? If you help to pay that much for someone else, then won’t you expect the same to be paid for you if you have the need? How can that be sustainable? Who gets to makes decisions regarding who we pay for and who we don’t? Unfortunate as it may be, it is a reality of life that we cannot afford, even as a society, to pay for everything we want. To the extent that those decisions, including limits on health insurance policies, can be made privately and voluntarily, we will have a more just, civil, and sustainable society.