Doctors can't give you all the right and real answers because they don't know all the right and real answers. As much as people would like to believe otherwise, medicine is not an exact science (why do you think they call it practicing medicine? ) As scary as it sounds, often making a diagnosis is a bit of a guessing game based on observation and elimination.
There is no possible way to learn, know and retain every little nuance of every possible disease. This is why doctors often specialize in just once branch of medicine; to try and remember it all is too overwhelming and honestly just not possible.
OTOH, too many people are willing to place complete control in the doctor's hands instead of taking some responsibility for their health themselves. Instead of educating themselves, they just want to be told what to do, be handed a prescription that will [hopefully] make things all better and be sent on their way. In the day when people were less educated and medical information was less accessible than it is now, that system worked fine (well, sort of), but today there's basically no excuse for not educating yourself on whatever disease you are dealing with, especially if it's a chronic one.