I'm not sure "obligated" is the best word to use here.
Doctors are put in a position to try to help people, but we, too, are human, and are prone to those things that make us humans. We make mistakes, sometimes we're wrong, and while it is certainly unprofessional, we also lose our patience. Sometimes there is just a personality clash that gets in the way of a good doctor-patient relationship.
Finding ourselves in the continual position of healing the sick tends to make many of us a bit egotistical too, and we don't like to be challenged. This is wrong, of course.
It's always a good idea to explain why you feel the diagnosis is this or that. But sometimes it's complicated, and with healthcare the way it is these days, the explanation is too lengthy and the waiting room is too full. But the short answer is you're right. You deserve a reasonable explanation, and you don't deserve to be judged or get a snotty answer. If you're not satisfied with the attention and answers you're getting from your doctor, it's in your best interest to seek another doctor.
I am not an orthopedist or neurologist, and i hope you don't mind my butting in to give an answer you probably heard before. Good luck.