Now that "... when did it EVER become okay for doctors to dismiss patients they couldn't cure..." is an interesting question. I asked my RN daughter who has worked in several large general and specialty hospitals.

Here is what I learned:
"It is called scope of practice. When you have a specialist, of any kind, they have a narrow "scope of practice" - sometimes dictated by the organization (clinic or hospital) where they work, other times by their comfort zone, and sometimes by their malpractice insurance and sometimes by the patients' insurers." And when you have a family doctor, Nurse Practitioner, Physician Assistant, Physical Therapist, etc - each of them has a defined "scope of practice" as well - for many of the same reasons.

So, in this age of specialization, if a doctor cannot help, you get sent to someone else.
The difficulty for patients is immense, especially in areas where there are not large integrated group practices, where the doctors can refer to others within their group.

My husband just experienced this in our winter home - serious bladder/kidney infection sent us to Urgent Care. After 2 rounds of treatment, the doc said "go see a urologist, here is one we recommend." I called, and they said "we can see him in 4 months" - Whoa, this guy was in intense pain and really sick! So after several tries, I was switched to a nurse, who said "Take him to this ER, if he is as bad as you say they will get him an emergency appointment with us." So that is what I did, and he got basic treatment and an appointment in 7 days - follow ups were tougher, but he was flexible.

I'm sure there is a good side to this - doctors who are not familiar with your condition don't "spin their wheels" costing you time and money without a solution. But that's no consolation when you cannot get an answer.

That is why you will often see people here suggesting that if you have been looking unsuccessfully for answers, it is time to find a large multi-disciplinary hospital or clinic where they have the specialists available to evaluate everything - Mayo Clinics (https://www.mayoclinic.org/appointments) is one, but there are others like Baylor in Texas.

Have you been seen in such a practice?
Sue