Keep this in mind... most of the heritage breeds or specific breeds also started out as "mutt" birds as they were being developed on the farms etc... Who knows you may be on to something with your own mutts!
You'll find as you get older, that this kind of drama isn't worth your time. Move on to other sites or create your own and don't let people get to you!
2x purebred dogs, cats, and chickens all started out by mixing different breeds with traits that where wanted