Damn , I've always been thinking like that guy in the cool quote .
also im thinking that we have earned that meat because humans originally are plant eaters and just a bit hunters , because we have no sharp teeth , no sharp claws and we are not so agile . anyway , we slaughtered biggest predators and made +[insert large and dangerous predator here] meat biscuits+ out of them .
Actually, primates are pretty much all omnivorous. Also, herbivores tend to make better snacks than carnivores for some reason, but your point still stands even if we didn't commonly eat the big predators.
You know why Africa has the biggest living land animals? They're used to humans, so they didn't get killed off by them until we brought in guns and stuff.
The amount of damage you'd do, and animals you'd kill, in converting enough land to feed all of humanity on plants alone, not to mention effects from alien species etc, would probably do fuckloads of ecological damage as well, in addition to overfishing, and as we wouldn't have a reason to keep nearly so many farm animals probably a lot less of them as well.
True enough, but animals aren't really more space-efficient, since they also need to eat. The solution is to implement more efficient farming methods and stop overpopulation somehow.