Arrogance, which I'd call exasperance in this case, in the face of repeated ignorance of reality, is justified. You can only deal with willingly ignorant people for so long before giving up on the human race.
And the doctor in the tale did try and educate the mother before she was cut off. She just didn't want to listen.
And the doctor in the tale did try and educate the mother before she was cut off. She just didn't want to listen.