They go around telling people not to eat meat for the same reason people go around preaching religion and bashing on abortion and stemcell research. They feel it is a moral subject. Personally I'm a pescetarian. I understand the vegetarian’s discontent. But I also understand that it is very hard to be a vegetarian, especially in America. Everywhere you go it is nothing but meat. The main course meal is always some kind of meat with vegetables as a side. There really are no vegetarian friendly meals almost anywhere you go. Sure there are salads and shit, but that isn't fucking filling. So you're pretty much forced to eat meat due to either convenience or availability. However, being a vegetarian is easily possible if you plan your food and only buy from food markets instead of eating fast food or at restaurants. But when you buy from food markets you run into the problem of organic and inorganic. The organic is healthier but more expensive = problem for some.
I love how we as human beings (well the majority anyway) go around feeling so good about ourselves believing we live in a predominantly righteous world, meanwhile we ignore this major problem. One second we can walk an old lady across the street and then the next second stuff our face with a fat burger and feel soooooooooo good about ourselves. Pure ignorance and oblivion. The situation with livestock is essentially enslavement in another form. The best way to think about it, is to think if life from elsewhere came to this planet and began harvesting us simply because they were smarter, and felt they were more important. We would be in the exact same position as the animals we harvest. There is a purely logical reasoning behind vegetarianism, aside from the moral reasons. The meat industry is one of the largest capitalistic foundations in the world and everyone supports it. They support the waste, greed, selfishness, and unhealthiness. And the funny thing is it is all avoidable if we were only less selfish. It's so amusing, parents going around telling their kids to share and be responsible, and especially don't be selfish, when the underlying aspects of society are all selfish and irresponsible by their very structure. The more you realize things, the more you realize the mainstream beliefs of society are far too often contradictive and hypocritical. It's easy to be stupid, it's not so easy to not be.
But yeah Menace your right, evolutionarily speaking we developed a vegetarian diet (somewhat omnivorous because we ate bugs). But once we took to the land we began killing other animals for food. If you look at the baboons they took a similar path. And actually we really haven't evolved out of our vegetarian anatomy. We have somewhat, that's why we still have our vestigial appendix (which once digested fruit and vegetation). However, meat is still hard on the body to process. Our body can process vegetation much easier. It is obvious we haven't fully evolved out of a vegetarian diet. And actually, we didn't really start eating meat on a large scale until we gathered into tribes and became hunters. Evolution eventually put us into the position of having to hunt or gather. Of course we did both, but we had to hunt out of necessity. Once we domesticated livestock, we realized that it was much easier to grow animals then to grow vegetation. That eventually changed but we stuck to meat nevertheless. And now we continue soley for profit. There are alternatives, however capitalism will never permit the growth.
If you’re against capitalism, waste, greed, and andtiprogressivism, then that should be enough for you to stop eating meat, otherwise you are supporting an atrocity.