The basic problem is that health care is a complex human system, not a set of mechanical boxes which can be moved around or replaced without affecting anything else.
John Goodman of the National Center for Policy Analysis made this point well:
Why is Washington having so much trouble reforming health care?
Why, if they do pass a major overhaul, are the problems of cost, quality and access almost certain to get worse?
Answer: Because they don't understand health care. By that I mean, almost no one in Congress understands health care as a complex system. When they campaign, most politicians claim that health care problems could be solved with a few simple reforms. Now that it's time to legislate, they are discovering that health care is very, very complicated. In fact, there is no solution that even comes close to being simple or easy.
As Nobel Laureate Frederick Hayek taught us, a complex system is a structure that is so complicated, that no one person can even begin to grasp it in its entirety. The best each of us can hope for is to master the small part of it we interact with.
Washington policymakers should take note. But almost by definition Washington policymakers don't believe in reality, so I'm not going to hold my breath waiting.