At best, Chiropractors are bullshit. At worst, they kill or paralyze people.
Their manipulations offer temporary pain relief because they forcefully mobilize the joint/bone structure. The only way to fix this long term is by correcting the muscle imbalances through physical therapy. Most people would rather get immediate pain relief vs months of therapy and exercise, so they have a constant supply of victims.
Chiropractic care should be outlawed as snake oil or health plans should stop covering it.