I have a friend who owns a sporting good store in New York. In the 80's he had a couple of just out of high school kids working for him who tried a couple of night courses at a local community college but due to lack of interest and effort, flunked most of them, and then eventually quit taking courses. They continued to work at his store as retail clerks. I got to know them on some ski strips the store sponsored. They were not even moderately intelligent. Their high school careers had been decidely middle of the road. Eventually I found that both had left employment at my friends store, when they were accepted at a local chiropractic college and they both somehow managed to graduate.
I would not even let either of these guys do a tune-up on my car, yet alone manipulate my spine. From what my friend tells me they are making a living as chiropracters, but are not making a good living. There are just too many of them near where he lives.
Some chiropracters do very well, often help some people, and are even somewhat honest: they are "mixers' (chirpractic obscure dogma jargon) who add to their bogus subluxations: a little physical therapy, a little natural food schtick, a little massage therapy, a little accupuncture, little supportive psychotherapy, etc.
Other chiropracters are true morons and rejects; they often drop out of business.
Many others are total frauds, bilking the public through endless fradulent insurance scams and as shyster co-conspirators.