That's all fair, but the context of the conversation was the present day, not the aggregate of all human history.
People who are not vegetarian but have never cared for or killed a farm animal were very likely (in most parts of the world) raised by people that have.
Even in the USofA much of the present generations are not far removed from grandparents who owned farms | worked farms | hunted.
The present day is a continuum from yesterday. Change can happen, but the current conditions are shaped by the prior conditions.