I breed both EEs and ameraucanas. It IS frustrating when someone markets their EEs as ameraucanas. It cheapens the work I do as a breeder to keep my line clean and up to standard. I do think that most people do it out of ignorance. Hatcheries though are a different matter. They should know better. It is an easy fix to label what they sell as Easter Eggers. Most people won't care as long as they lay pretty eggs.
I disagree with the notion that a pure ameraucana crossed with another pure ameraucana can produce anything but an ameraucana. I don't know why we don't just call them non-standard ameraucanas and be done with it. In my head an easter egger is a pure ameraucana crossed with something else. I get mine by having an ameraucana rooster over buff orps, wyandottes, welsummers and barred rocks. None of the offspring breed true and you never know what you will get with combs and egg color. They do pretty consistently come out with cheek muffs. Combs are mostly pea, but I do get the occasional single comb in my EEs.
Breeding AM to AM though always gets bluish eggs, pea combs, cheek muffs and the right colored legs. Feather colors might not fit the standard if I breed a splash to a wheaten, but technically the bird is still an ameraucana. I understand saying "This bird is pure wheaten ameraucana" or "pure blue ameraucana", but AmxAm gets you AM. Saying that it is magically an EE because the feather color is off is silly.
That sort of sematic bickering also cheapens the breeding work because it opens the door for people to say "Oh well, they are just being snobby about color." and assume then that the hatcheries are correct. If the APA would just say "AM x with anything else equals Easter egger" and "ameraucana x ameraucana equals ameraucana" it would be easier to pursuade the hatcheries that they are using false advertising.