So, I'm not quite sure I understood you, but you seem to be explaining how someone might come to believe that ethics are universal/objective in the sense of right action not depending on the actor or the situation at all, even at relatively low levels of specification like "eat more vegetables" or whatever.

Did I get that right?

If so... sure, I can see where someone whose moral intuitions primarily derive from obeying the commands of others might end up with ethics that work like that.