Look at it this way:
Say there's a disease called Deathabetes that primarily affects elderly people. Sheisa Pharmaceuticals develops a drug called Death-B-Gon that, on average, extends the life of a Deathabetes sufferer for 1 year. Now, if that drug cost $10, I would assume that every one of us would agree that Medicare should pay for it. If the cost were $5,000, I think most people would still be on board. But what it it cost $50,000? $500,000? $50,000,000?
At some point, everyone would have to agree that the drug becomes too expensive to be worth its benefit. We face this exact same dilemma with thousands and thousands of drugs and procedures today, ranging from hip replacements to cancer treatments. How the balancing point is calculated is incredibly important.
One of the reasons why insurance costs continue to increase is because of special interest groups that lobby insurers on this exact issue. First, a breast cancer group raises a stink about an insurance company refusing to pay for a particular expensive drug. Not wanting the bad publicity, the company agrees to pay for that drug. Then a Parkinson's group does the same. Then a MS group, then a Sickle Cell group, etc. The end result is that most everything ends up getting covered and the rest of the costs get passed on to everyone else.
When the decisions are being made by insurers or politicians who are subject to the fleeting will of the public, inefficient choices are going to be made. The only way to get around this is to have the people making the decisions be as independent from public control as possible. Britain tried to do just this by creating the NICE, but despite that program's successes, it has still fallen prey to some of the same interest group capture.
Here is the stark reality that neither Republicans or Democrats are willing to admit: So long as we as a nation continue to place such an incredibly high value on the availability of expensive life-saving treatments, we will never bring health care spending under control. I don't see such a significant cultural shift happening any time soon.