You asked about two bad teachers:

For what it's worth, I bet they aren't bad teachers. DD has had ONE wholly positive experience with a teacher. The rest have been really rough, including the gifted teacher. A very good, very experienced teacher is not going to look very good or experienced when presented with a very unusual kid. The fact of the matter is that the teacher doesn't have experience with a kid like yours. The situation is compounded by the fact that they don't likely have the resources to figure out why your kid isn't clicking with the situation. After all, she's got tons of experience! So her logic is likely to go along the lines of "well, I'm super experienced, and if my big bag of tricks isn't working in this case, it must be the kid.". We've even encountered this for two teachers this year who have looked me in the eye and stated "In all my years of teaching, I've never encountered a kid like yours."