Chiros would be better off if they stopped over-hyping their service. There is a concept in sales called "talking yourself out of a sale." This occurs when you have talked someone into signing on the dotted line, but instead of closing the deal at the first chance, you keep yammering until you've said something to make the customer rethink their choice and walk away. This is exactly what chiros do.
I find it to be a pretty reasonable idea that low back pain might be caused by misalignment of the spine, and that symptoms could possibly be alleviated through manual manipulation. Tell me that, and I might give it a try. But then you start telling me that a) infants should have a chiro adjustment immediately after birth b) chiro adjusments can cure everything from allergies to cancer, and c) everyone--including asymptomatic individuals--needs chiro treatment. By the end of the spiel, I'll be ready to walk out the door.
Stop calling yourselves doctors (in the medical world, that term refers specifically to physicians). Stop claiming that you can accomplish miracles by cracking my back. Stop telling me that I need your service whether I have symptoms or not. Just tell me what you can actually reasonably do for me. Maybe once you've told me "we can't cure cancer, but we might be able to help with your back pain by getting some things realigned" I might be willing to give it a try.