Oh, well as long as they're only practicing medicine without a license, I suppose that's okay then...
Except at least in the McDonald's case you have to eat food to survive, so you may not have a choice. You don't have to go to a chiropractor to survive, so it's better to not go there at all than it is to go and receive possibly dangerous treatment from a con artist.
Remember, there is no science behind what they do. They don't know if they're going to hurt or paralyze you because they never went to medical school!!
Psychiatrists are also Doctors of Medicine and can prescribe medicine. Other mental health professionals (Licensed Professional Therapist, Licensed Marriage and Family Therapist, Psychologist) are not and provide therapeutic interventions.
EDIT: I just realized I'm coming at this from a USA-centric point of view. I have no idea how this applies to other places.
I don't really understand what people need a physical therapist for... They basically just instructed me on how to do exercises that significantly worsened my pain. Brilliant? And then she had the nerve to say riding my bicycle is a bad idea?! Fuck that stupid bitch I never went back.
My chiropractor was much more pragmatic. He asked if bicycling made my back feel better. Guess what?! It does!!!
While a massage therapist or chiropractor does things I can't do to myself. So PT seems kind of like a waste of time and money.
I suggest Bob and Brad on YouTube. Do it at your own pace and do things that actually feel good and don't hurt!
Yeah, but them very same type of folks (like where I grew up in "rancher territory") who can't (or won't) regularly spend on "woowoo crap" will happily budget a reasonable monthly (or even weekly) fee for a bit of good advice, some stretching exercises and "adjustments", and a bit of basic applied physical therapy techniques that provide a measure of genuine relief. That's how chiropracters in "farm country" make their money.
They basically are as you say "practicing physical therapy" (and some other similar and related services) under a different license (chiropractic). If they didn't provide a valid service in places like that, they'd be outta business downright quick-like, because them small-ish towns, word gets around pretty quick if you done somethin' bad like scammin' a hard-workin' neighbor with "woowoo crap".
Because rural areas are immune to scams or quackery? I think you'll find them just as immune as city folk.
In my area someone's insurance might cover the first 3-4 sessions of physical therapy, but nothing after that despite them needing it for longer. So the physical therapist will at the end of insurance billing send them down the road to do the exact same thing at the chiropractor for significantly cheaper.
In places without a lot of manual labor they are probably mostly just the quackery. Their clients are lots of hypochondriacs and office workers who really just need to get more exercise but are willing to find anyone who says they can make them better without significant effort. Im sure the massages and stretching does feel good though atleast, but im sure a massage parlor would set out some crystals and do a massage for cheaper.