Because there are very strong forces interested in maintaining the status quo.
Washington Post columnist Robert J. Samuelson finds that American health care system (via Robert Centor) is a reflection of our society: “It’s highly individualistic, entrepreneurial and suspicious of centralized supervision. In practice, Medicare and private insurers impose few effective controls on doctors’ and patients’ choices. That’s the way most Americans want it. Patients understandably desire the most advanced surgeries, diagnostic tests and drugs. Doctors want the freedom to prescribe.”
That being the case, any effort to control costs is bound to run into resistance. There is no constituency that will advocate for spending controls, since “most patients don’t pay medical bills directly, they have little interest in using less care or shopping for lower-priced services. Providers (doctors, hospitals, drug companies) have no interest in limiting care.”
Indeed, health costs to some people may be the wages and salary of others.
Controlling costs means less, for both patients and doctors. Both groups need to buy into that in order to have any shot at controlling costs.