My sympathy here is dependent on the nature of the complaint.
A possible problem with this framing is that the U.S. is the world capital of unnecessary medical care. Figure 2 here only compares three other nations with the U.S., but gives the idea. This of course is related to American health care being the most expensive without giving the best outcomes.
Most complaints I hear about are care denials. What you will not hear about is everyone who died because the gatekeepers were not rigorous enough in stopping unnecessary surgeries.
There’s a good argument that profit-making insurers like UnitedHealthcare should be transitioned to a non-profit model. But even though I generally recommend non-profit insurers when you have a choice, those also need strong gatekeepers – generally speaking, stronger than we have now.
Every heath care system, including ones that are more highly socialized, has imperfections and aspects that anger patients. One job of health care executives – profit, or non-profit, or socialized – is to reduce that, but it also is a legitimate, socially valuable, part of their job to disincentivize unnecessary care. That inevitably angers patients who think the care would help them. I hope this isn’t seen by anyone as justifying violence.