Slate has a pretty solid history of telling vegetarians what to think. This piece was actually really persuasive about the case for vegans eating oysters, by using such things as research and logic. But Lowder's piece makes clear only one thing: J. Bryan Lowder is kind of a dick.
His entire argument about why chickens shouldn't count as meat can be summed up thusly: "Chicken stock makes tasty food." It's the perfect rebuttal to the argument no vegetarian has ever made, "I'm a vegetarian because I think vegetable stock tastes better." Sure, chicken stock may be "Considered foundational to many of the world’s cuisines", but beef is also considered foundational to many of the world's hamburgers. Whether or not you agree with my reasons, you can't possibly believe I'm eating veggie burgers because I think they're better burgers.
While knocking down this straw-chicken argument, he continually reminds us that the article is really about what a lousy person he is: "When I have vegetarians over for dinner, I’m already making a sacrifice by forgoing a real entrée in favor of a meatless one." Is that what you're doing? Or maybe they're sacrificing their time hanging out with you instead of somebody who doesn't say "real entrée" about the food they choose not to eat. He also triumphs over vegetarians using the famous Color Argument: "vegetarians shouldn’t make a big deal about some small amount of a near-invisible (if crucial!) liquid". I remember all those great ethics classes in college where the professor would say, "It doesn't count as killing something if the result is a clear liquid."
I'm glad you're using all of the chickens, Bryan. But when you say "I’m being a responsible, frugal meat eater by doing this—can’t vegetarians acknowledge my effort by letting slide the few tablespoons that might end up in their soup?" it really seems like you're writing more about why you're a terrible friend than why I'm a terrible eater.
I've been a vegetarian for over a decade. I know that makes me annoying to have at dinner parties, nobody is more aware of that than me. But I'd rather go to a dinner party with three vegans, two slow-carbers, and one person on an elimination diet (actually, that's a pretty standard Portland dinner party) than one J. Bryan Lowder.