Ultimately there will always be some healthcare rationing. This happens in every country. For example, the UK NHS has death panels which decide that certain treatments won't be covered at all because they're not cost effective. Resources are limited and demand is effectively infinite. So the only real question is how we do the rationing.
UHG has been caught denying claims for things that employers already paid them to cover for their employees. You can't blame HR departments for that. You also can't blame HR for UHG upcoding/overbilling which eats into the limited resources of hospitals and the limited resource of taxpayer money ultimately resulting in fewer people able to get the healthcare they need just so that UHG can line their own pockets.
While HR departments do have their own issues, they're nowhere near the level of pure evil that UHG is.
The work to upstream our changes was included in the Statements of Work which Walmart signed off on, and our time spent on those efforts was billed to them.
The stats for those projects will have recorded my former employer as the direct source of those contributions - but they wouldn't have existed had it not been for Walmart.
Yes, I've also worked on OpenStack components at a university, and there I see Red Hat or IBM employees pushing up loads of changes. I don't know if I've ever seen a Walmart, UnitedHealth, Chase Bank, or Exxon Mobil (to pick some of the largest companies) email address push changes.