Not just psychiatry! Why does medicine in general ignore this?
Possibly because a substantial number of medical practitioners have a very different view of PwME (essentially as neurotic) from the one we'd like them to have (seriously physically ill), and though the ones who care to look at all no doubt see the bad science they probably see the treatment arising from that bad science as quite suitable for patients who always seem to be darkening the doors of their surgeries or clinics complaining of innumerable vague ailments but who seldom have anything detectably wrong with them.
PwME are nothing but a source of irritation to a significant proportion of the medical profession, and if the treatment the psychologists had come up with was immolation on open pyres I'm sure there are some practitioners who wouldn't consider it inappropriate treatment for this particularly troublesome group of nuisance patients.
How we are perceived by others is often radically different from how we perceive ourselves, and PwME are probably one of the most extreme examples of this phenomenon at work.