The arrest in the slaying of UnitedHealthcare CEO Brian Thompson was the first step to putting his alleged killer behind bars, though it won't end the power struggle in health care illuminated by public reaction afterward.

Another wave of criticism rose against Minnetonka-based UnitedHealthcare, the nation's largest health insurer, and the broader insurance industry following the arrest on Monday of Luigi Mangione. The 26-year-old scion of a wealthy Maryland family was charged with murder for shooting Thompson last Wednesday outside a hotel in New York, where the executive was headed to an investor conference.

A new extreme in the diatribes online emerged: entrepreneurs selling fake UnitedHealth T-shirts with the words that were written on bullet casings found at the shooting scene. Amazon removed some such merchandise from its e-commerce store.

In a column last Friday, I tried to place the "absence of empathy" for Thompson in the context of other news events, ranging from mass shootings to goof-ups by athletes in their sport. I also tried to convey the powerlessness that many Americans feel about health care. And I ended by writing that killing people and acting rudely online are unlikely to solve the problems.

Readers stuffed my email box with feedback, the most for anything I've written this year. I took that as another sign of the strong feelings and conflict surrounding health care in America. While some readers said I conveyed the tension well, more wrote that I seemed oblivious to the anger people feel toward those with power over them in health care.

"To tell people they should be sad or respectful when someone they view as bad dies, just makes it seem like they should forget all the harm caused," reader Emily R. from Isanti County wrote.

"For people still paying off piles of medical debt because of denied claims, people who lost someone because they could not afford insulin or other meds, it is the only sense of justice that they will ever get. Then you came along and scolded them for being mean," she added.

UnitedHealth Group, the parent company of UnitedHealthcare, has said nothing publicly about the outcry, though others in the insurance industry have. UnitedHealth Group CEO Andrew Witty, who was Thompson's boss, addressed it in a video to employees that leaked on Friday.

"I encourage you to tune out that critical noise that we're hearing right now," Witty told employees. "It does not reflect reality. It is simply a sign of an era in which we live. What we must do is focus on what we know to be true. And what we know to be true is that the health system needs a company like UnitedHealth Group, and it needs people like Brian within it."

In another part of the video, Witty said, "We guard against the pressures that exist for unsafe or unnecessary care."

There is no doubt that doctors and hospitals sometimes push more treatments on people than needed, and insurers' role is to push back and prevent overspending. The FBI estimates fraud and abuse account for 10% of health care costs, and other estimates go as high as 15%.

That power struggle will outlast this moment. But consumers are always left to wonder: Why do publicly traded insurers get to decide when care is warranted, when they may be more motivated by investors' interests than patients'?

Americans pay the highest prices for care in the world, but their health outcomes are not the best. No one really knows what services cost and why, and no one is certain what insurers will cover and when.

Grief over Thompson's death will last for a long time, particularly with the people at UnitedHealth who knew him well. In time, however, some of the leaders at UnitedHealth will have to join the public discussion.

The vitriolic response to Thompson's death put in a crucible all that's going wrong. Stat News, the Boston-based health care news site, called it "a defining moment in the zeitgeist of American health care."

Witty, a Brit knighted in 2012 for a distinguished career that led him to the top of U.K.-based pharmaceutical maker GlaxoSmithKline, knows there is nothing like America's insurance system nor a company like UnitedHealth anywhere else in the world. The U.S. is the only developed country without universal health coverage.

Gallup, the opinion research firm, on Friday announced its latest survey of Americans' attitudes on the quality of health care showed them to be at the lowest point since it started the annual survey in 2001.

As I heard from more readers through the weekend, a few suggested other tensions at play. Some cited the tone of the presidential campaign, particularly President-elect Donald Trump's rhetoric, for the uncaring words toward Thompson. Joel Stegner of Edina mentioned another hot button issue: "The tragedy of this case is that if someone wants to murder you with a gun, there is not much you can do to prevent it."

Tom Koehler of Two Harbors wrote about misplaced values. Now 77 and retired, he spent 32 years as a tradesman working on railways in Minnesota "building and tearing up track, repairing faulty track, and welding and grinding railroad rails."

He wrote, "When I did my job right, trains stayed on the tracks and had a smooth ride. There was no performance bonus. As a worker I was regarded as an expense rather than an asset."

He then added, "When the insurance CEO did his job well, people were denied payment for the health care they received or were denied the health care because it was not covered for some reason, even though it was warranted by the treating physician. People suffered and the insurance company's profit went up. Not one thin dime of health insurance profit ever did anything to benefit a person's health. Good health is as much a strategic good for a nation as a strong military force and a sound manufacturing base."