I've always had a problem with this argument, but I think I finally understand WHY I have a problem with it. For the record here, I don't think big corporations like Walmart and Amazon are inherently good or evil- they just sell goods and services to people who are willing to buy them at market prices. But if my ethical system did include the belief that all corporations are evil, I don't think I'd also hold the belief that all corporations are equally evil. Saying that there's "no such thing as ethical consumption under capitalism," by rhetorical sleight of hand, has come to mean that everyone of leftist leanings is completely absolved from the responsibility of finding the way to obtain goods and services that best aligns with the beliefs they profess to hold. In practice, this means that every time Kevvo could buy his robot toy from a local department store instead of a nationally owned supercenter, he's allowed to wave away the blatant contradiction between the beliefs he says he holds and the beliefs he actually holds with a pithy slogan.