Why do people go out of their way to put the profession of Chiropractic down?

People will refer to Chiropractors as quacks and not doctors. To me, a doctor is anybody that helps people with their physical ailments and that has gone through schooling to get their, degree, certificate, license, or registration. Are people really that crazy? What did chiropractors do to these people to cause them to spew their hatred by any means necessary? DAMN!!!