Because there is absolutely nothing wrong with eating meat, especially if it's done in the right moderation. Also, meat is delicious. Animals were put on this planet to feed other animals, aka carnivores and omnivores (and guess what, humans are omnivores!).
If you choose not to eat animals, then that's your own personal choice. But there is nothing more annoying or retarded than a fucking hippie vegan trying to tell everyone else that they're wrong or terrible people for harming those poor, helpless animals. Enjoy your tofu....meanwhile, I'll be enjoying my delicious rib eye steak.
And FYI, humans were able to develop further and faster in ancient times when they learned how to catch animals and cook their meat over fires to help break down complex nutrients (and the human body was able to absorb and better utilize said nutrients) which helped develop the human brain in ways that could never be done with simply eating nuts and berries.