No see thats the entire crux of the argument, they cant just ignore what makes a burger a burger and call a chicken sandwhich a burger anymore than I can call salmon with mash fish and chips... either the definition means something or we can just add whatever we want because its close. Salmon and mash is still fish and potatos like fish and chips is. Just the potato is a different form. Just like a breaded fillet on a bun is still protein on bread, just in a different form. So either both are acceptable or a chicken fillet on a bun is not a burger.