"MG is the most well understood AI disease"

Do you think they still seriously believe it?
I know my neurologist doesn't think so. He thinks it is the most "crazy" and least understood disease there is.

But, I think you are right that it is very convenient for everyone to repeat those "mantras" and just keeps things the way they are.

The fact that most patients do well with or without treatment is probably a factor as well.

And also the fact that neurologists have a very convenient way to deal with their lack of understanding and knowledge. In fact if the DSM-5 revisions are accepted it will be even more convenient. They will not even have to prove that the patients has "emotional problems". Their lack of knowledge and understanding will be enough.