Sorry, but "pre-Pomo Marxist literary criticism" counts as name-calling on an internet forum, unless you do something to make it clear you don't intend it that way—and you did just the opposite. Also, while I don't know anything about cstross really, I strongly doubt that he's a Marxist. The odds of an internet commenter spuriously spouting "Marxist!" are much higher. At a minimum, you'd have to make a serious case, which you didn't, hence the epithet "unsubstantive".
Look at it this way: if you reduce someone's post to a theory you regard as stupid, as a reductio ad absurdum, you're narrowing the discussion rather than expanding it. We want curious conversation here. That's a different mentality. We all have it in us to do both—close down or open further—but unfortunately the default is closing down. On this forum, the idea is to go against the default for great good.