There is no such thing as a legit chiropractor. Objective studies have been done over and over and shown it to be pseudoscience.
If your chiro is doing you any good, it's because either:
1. In addition to chiropractic, he's also engaging in massage or other physical therapy, or
2. It's all in your head.
If by "adjustments," you mean he's one of those guys who tells you that he can solve health problems anywhere in your body by realigning your spine, then it's probably the latter. It's quackery.
It's just not that black or white situation. There are "quacks" in every line of work. Did you watch Making a Murderer? Those lawyers ....geez. I went to my doctor for my back/hip - shooting pain issues and nothing worked. Then I went to my chiro and he fixed it almost instantly. I know some cases should go to a doctor but there are plenty of cases where alignment takes pressure off nerves and fixes issues. My wife's grandfather deteriorated so that he couldn't walk by himself. He went to all the doctors and nothing helped. He decided to try Chiro and it totally changed his life. It was like he was 20 years younger in his movement.
I don't have a dog in the race, I'm not a Chiro or a Doctor but saying it is total crap 100% of the time is silly.