That's called the naturalistic fallacy, and there's a clue in the name that should indicate how reliable an argument it is.
And re "nutritionally inferior", every dietetics and nutrition peak body on the planet agrees that a fully vegan diet is suitable for all people throughout all stages of life. In fact, billions of people have already lived perfectly normal, perfectly healthy vegan and vegetarian lives throughout history. If your diet — any diet — is nutritionally incomplete it's because you made the wrong choices.
And re "nutritionally inferior", every dietetics and nutrition peak body on the planet agrees that a fully vegan diet is suitable for all people throughout all stages of life. In fact, billions of people have already lived perfectly normal, perfectly healthy vegan and vegetarian lives throughout history. If your diet — any diet — is nutritionally incomplete it's because you made the wrong choices.