You can say that you are murdering people by posting on HN instead of working more and donating the money to charity.
>At what point is defending their murdering of people an acceptable approach? :)
We have laws that define where your responsibility starts and ends. For a random citizen, you have 0 obligation to help someone pay their healthcare bills.
For a health insurance company, they have a legal obligation to spend 85% of revenue on member healthcare, with all expenses and profit coming from the remaining 15%. This is codified by the ACA 85/15% law passed under Obama. United meets this obligation.