Sounds like prejudice to me too!! Im not sure you'd have to go through a one-to-one if you had ie a Lab even if he was a gobby Lab! The trick is to find a class whose trainer also owns GSDs, like the classes we used to attend with Diva (trainer had 5 GSDs!)and you wont get faced with this sort of behaviour...but yes easier said than done
Diva used to bark the class down when we got there as she wanted to be let off leash to play with the other dogs and nobody minded.
Having met Ted, I cant believe he wouldnt be suitable for any class, he's such a good dog. Hope you find the right class soon xx