The only reason the author seems to give for not eating animals is some vague sentiment of its inherent cruelty, whatever he means by that word (harming things with eyes? Does he eat potatoes?). Is it somehow less cruel to raise crops from the ground, reap their delicious parts, and then slaughter them wholesale by plowing them back into the ground?

To suggest that animals are superior to plants is speciesist. At least animals can defend themselves, or at least make attempts to run away or escape. Plants are essentially defenseless, and everyone knows that harming defenseless creatures is the real cruelty. That's why I refuse to eat anything that didn't have at least a plausible chance of fighting back or running/flying away.