I agree. My point thought was not primarily about the child comment being voted up, but about the child comment being an insightful critique of or counter-argument to the parent. In the example, the child comment being voted up was just meant as evidence that the comment actually 'does' make a great point that needs a response from the parent, which is why it's so disappointing to see the comment ignored.

The status game I had in mind was "if I ignore that comment that points out serious flaws in my argument, people will be more likely to get the impression that the comment is not worthy of reply and that my argument really isn't flawed, and I can avoid a response that might lower my status, even if that compromises the rational, educational aspect of this site." The irony is that for many of us here, responding would actually be a status-enhancing act.