Doctors know very well that a person with a specific rare disease has a lot more incentive to have spent in-depth research on it than they did when they last ran across it...
I mean, these days there are whole forums dedicatd to a specific disease. If you told the doctor, "You know, I ran across a forum for people like me, a lot of people have said they had very bad results with (x) despite the clinical trials, so I would prefer (y)"...you don't think they would listen to you?
Where is this attitude coming from?