1. fwiw uhc has two businesses, united health care and Optum, which is not health insurance. the profits are split pretty evenly between the two. i dont know if other insurers have a similar side business. if not, then comparing profits is apples to oranges.
2. here's a line from the "risks" section annual financial report that explains the problem:
If we fail to develop and maintain satisfactory relationships with health care payers, physicians, hospitals and otherservice providers, our business could be materially and adversely affected.
note the absence of patients or members from that list. almost nobody with united health insurance is choosing to use united health insurance (maybe it's constrained for some people whose employers give them two options but its not a free market). someone else makes that decision. so they cater to someone else. as long as patients are 3rd party beneficiaires of employer-insurer contracts, pateints are going to get screwed.
i guarantee the system would be better with a) a mandate to buy insurance; b) everyone buying their own plans; c) retention of obamacare standards for required coverage and d) subsidies to make a) feasible. that might not be the best system we could design but it would be better than this.