Willa,
I understand your frustration, and I do know a few teachers who do the very least they can. However, I really believe that basically, they just don't have a clue about how to identify a gifted student, especially a profoundly gifted student, and definitely not a PG student who also has learning difficulty in other areas. I know that at least in Australia, we are completely unprepared to meet the needs of such students. I believe teacher education is mostly to blame - at least here in Australia.
Well, that's my opinion - coming from an ex-teacher who really did care about students - so much that I had to leave the job - it is just too difficult to do the job as well as I would like. I would have to work 24hours a day, 7 days a week and even then I wouldn't be fully meeting the learning needs of all the students in my class. It's terribly frustrating - for teachers, parents and students. And very sad, too, especially for the students.