Any time a sentence starts with "Why atheists should be_" you can be reasonably sure that what follows will be nonsensical crap. In this regard Vlad Chituc's "Why atheists should be vegans" post on Patheos does not disappoint. From start to finish it is some of the dumbest bullshit I've read from a fellow atheist in quite sometime. Even after setting aside that atheism isn't an actual "ism" and therefore has no identifiable set of beliefs that any of his ideas can be supported from, he makes a number of incredibly blatant errors.
Not only does Chituc fail to make any type of connection between atheism and veganism he grossly characterizes and conflates a variety of issues. It is highly debatable as to whether veganism is more ethical especially when you apply what this dumb-ass actually says about it. He actually isn't making a case against eating meat in general. He makes this clear from the very first paragraph which he ends with "...most atheists nonetheless have no good reason to consume factory-farmed animal products." It is true that the majority of meat consumed is from factory farming and it can be argued that this is unethical. However, this is misleading in that it cannot presently be used to advocate for "veganism." The overwhelming majority of produce consumed also comes from "factory farming" which has a whole boat load of ethical issues attached to it as well. Does Chituc really think that industrial scale agriculture has a squeeky clean record when it comes to labor rights or environmental issues?
Eventually he does get to purely animal rights arguments which do not depend on the methods and techniques used to raise, care for, and slaughtering of animals. It seemed to be more of an after thought than part of his main points. Perhaps he realised how weak and feeble his argument up to that point had been. They are still far more debatable than he seems to realize. He references science but in vague and misleading ways. Utimately, he fails to make a connection between a lack of religious beliefs with advocacy of veganism or animal rights.