> They would just either tell me to stay in a corner and sleep or just draw pictures, flowers for them
It doesn't take a specialist to recognize something's off (the fundamental assumption is that, barring a diagnosed learning disability, everyone is able to learn to read and write), and you don't need a full time specialist to do a one-off diagnosis. Whether they had the budget for continued full-time support after that (ex: preparing accessible teaching materials) is a separate question.
TFA is light on details, but it's hard to imagine everyone was doing the best with what they had here.