I think that most of the people arguing the position do so in bad faith.
They know it's an oversimplification to the point of absurdity, but they want to bog their opponents down in explaining why it's an absurdity, and/or catch them in a minor lack of rigor which can be used to refute every other point they've made, and/or be able to retort with red-baiting along the lines of "why don't you believe markets work? Are you a commie?" It's about controlling the topic of conversation, rather than coming to a mutual understanding about the way the world works.
They know it's an oversimplification to the point of absurdity, but they want to bog their opponents down in explaining why it's an absurdity, and/or catch them in a minor lack of rigor which can be used to refute every other point they've made, and/or be able to retort with red-baiting along the lines of "why don't you believe markets work? Are you a commie?" It's about controlling the topic of conversation, rather than coming to a mutual understanding about the way the world works.