Magic medicine and Insurance
Note: By chiropractic care, I mean the traditional Palmerian subluxation nonsense. The term "chiropractic care" is presently applied to many types of treatments, loosely or not at all related to Palmerian treatments. I do not wish to debate each individually. WWW.CHIROWATCH.COM will handle that.
The answer is that this legitimacy is no more legitimate than an endorsement from a celebrity. Insurance companies sell what people demand, not necessarily what is good for them. For example, the Aetna site often comments on quackery, but there may be Aetna plans that cover the same quackery, because their job is to sell policies, not to dictate medical treatment. I am sure that if a company targets religious Jews, they may yet sell insurance that covers the pidgeon treatment for hepatitis. This does not imply research, only market demand.
Another challenge I get is that, since some things work as placebo, we should allow it to work for the people who would benefit from the placebo. This is OK, but magic medicine practioners often pick up on people who are in desparate straits, who have tried real treatments, or have been convinced that medical science is a monetary conspiracy. After all, who would not spend a moderate or even large amount of money for a promise (and that's all there is, a promise) to save themselves or a loved one from a difficult disease. They are no more than a con game for the vulnerable. I think that victimizing people in this way, especially under those conditions, is reprehensible, disgusting, despicable, I can not think of strong enough terms. Apparently, a large number of people in the frum world disagree, by posing this challenge. I guess our moral standards are different, as well as our reality compass.