I'm pretty sure that this is a normal feature of human cognition and psychology.
Severe intellectual deficits ----> Relatively easy to understand
PG kids ----> Relatively hard to understand
So, this problem is not going away and will remain perpetually frustrating.
Not to put too fine a point on it, most people can comprehend severe intellectual deficits even if they have not encountered individuals with such deficits before. It may take them a little while to fully grasp a given individual's abilities and boundaries, but they do have an internal frame of reference and thus a mechanism by which to calibrate and understand deficits. In contrast, most don't have that personal frame of reference for PG abilities. It takes imagination and a willingness to be surprised and let go of what is "known" or usually expected. Many parents of PG children struggle to do this when their children are little, and most educators have had far less exposure to PG individuals.
