First, I joke that if I were to be reincarnated as a foodstuff I would rather be a lamb than a lettuce, because at least I'd not be eaten alive.
Then I get serious and ask what foodstuff would replace the sheep that currently graze on all the areas where only grass will grow? And are they happy that total vegetarianism worldwide would lead to the extinction of all the species and varieties that we currently eat, and therefore whose populations we manage, because they would become competitors?
I have no objection to anyone eating whatever they like, as long as their dietary restrictions aren't imposed on anyone else. I don't eat a lot of meat as it irritates my gut; ditto grains, particularly gluten-containing ones. For red meat, I prefer kangaroo to beef. I think it tastes nicer; plus roos need far less food than cows because they have different intestinal flora which generate acetate (digestible) instead of methane (a major greenhouse gas). They also don't have hooves to destroy the paddocks. So they are environmentally friendly!
