Similarly shouldn't an insurance company have the option of not renewing your coverage if you develop an expensive to treat disease?
Similar to an auto insurance company dropping you for too many claims.
I could see that as an option to be battled in the marketplace, but the original idea was for insurance only to cover expensive treatments.
Maybe the comparison would be if you were obese and smoked they wouldn’t cover diabetes or lung cancer.
If someone gets in a car wreck, the insurance company may decline to renew one's coverage, but doing so would not excuse the company from paying for future costs associated with the wreak. If "medical insurance" were actually insurance, the same principle would apply to major illnesses. For example, if someone had a cancer policy and developed cancer while the policy was clearly in effect, the policy would cover all lifetime costs associated with the cancer treatments indicated in the policy. Declining to renew the policy for someone who developed cancer wouldn't help the insurer, since it would still be on the hook for treating the person (note that if the policy is only required to treat people with the methods indicated therein, it should be possible to reasonably predict the expected lifetime cost per patient who develops cancer; of course, the vast majority of policy holders wouldn't develop cancer, so the costs of paying for those who do would be divided among the much larger pool of those who don't.