Criticism of alternative medicine

Alternative medicine is commonly categorised together with complementary medicine under the umbrella term 'complementary and alternative medicine' (CAM for short). Some scientists reject this and the above classifications and to varying degrees reject the term "alternative medicine" itself.
The following four commentators argue for classifying treatments based on the objectively verifiable criteria of the scientific method, not based on the changing curricula of various medical schools or social sphere of usage. They advocate a classification based on evidence-based medicine, i.e., scientifically proven evidence of efficacy According to them it is possible for a method to change categories (proven vs. unproven) in either direction, based on increased knowledge of its effectiveness or lack thereof:
Marcia Angell, former editor-in-chief of the New England Journal of Medicine, states that "...since many alternative remedies have recently found their way into the medical mainstream [there] cannot be two kinds of medicine - conventional and alternative. There is only medicine that has been adequately tested and medicine that has not, medicine that works and medicine that may or may not work. Once a treatment has been tested rigorously, it no longer matters whether it was considered alternative at the outset. If it is found to be reasonably safe and effective, it will be accepted."
George D. Lundberg, former editor of the Journal of the American Medical Association (JAMA), and Phil B. Fontanarosa, Senior Editor of JAMA, state: "There is no alternative medicine. There is only scientifically proven, evidence-based medicine supported by solid data or unproven medicine, for which scientific evidence is lacking. Whether a therapeutic practice is 'Eastern' or 'Western,' is unconventional or mainstream, or involves mind-body techniques or molecular genetics is largely irrelevant except for historical purposes and cultural interest. As believers in science and evidence, we must focus on fundamental issues—namely, the patient, the target disease or condition, the proposed or practiced treatment, and the need for convincing data on safety and therapeutic efficacy."
Richard Dawkins, Professor of the Public Understanding of Science at Oxford, defines alternative medicine as a "...set of practices which cannot be tested, refuse to be tested, or consistently fail tests. If a healing technique is demonstrated to have curative properties in properly controlled double-blind trials, it ceases to be alternative. It simply...becomes medicine."He also states that "There is no alternative medicine. There is only medicine that works and medicine that doesn't work."
Stephen Barrett, an alternative medicine critic, argues that techniques currently labeled "alternative" should be reclassified as "genuine, experimental, or questionable. Genuine alternatives are comparable methods that have met science-based criteria for safety and effectiveness. Experimental alternatives are unproven but have a plausible rationale and are undergoing responsible investigation. ... Questionable alternatives are groundless and lack a scientifically plausible rationale. ... Blurring these distinctions enables promoters of quackery to argue that because some practices labeled "alternative" have merit, the rest deserve equal consideration and respect. Enough is known, however, to conclude that most questionable "alternatives" are worthless."
Other well-known proponents of evidence-based medicine, such as the Cochrane Collaboration and Edzard Ernst, Professor of Complementary Medicine at the University of Exeter, use the term "alternative medicine" but agree with the above commentators that all treatments, whether "mainstream" or "alternative", ought to be held to standards of the scientific method.