I think people blame the people they cannot help. So it becomes "they are making it up" instead of "we have limits to what we know"
Any number of things go untreated and mistreated and people stop trying to get help because they are dismissed as having nothing really wrong with them because western medical science could not or did not find the problem. People with thyroid disease symptoms, Fibromyalgia, and other things have been dismissed for years. I find the attitude of western medical providers to be insulting and wrong when they take the view that nothing is wrong and you are not having pain just because we can't diagnose it. It is another reason why I only use eastern medicine. And have a field day when I get involved in these type cases as an attorney.