It's not legit to flag an article just because you don't like the general category. There must also be something about the specific article itself that's demonstrably bad for HN (for example, maybe the article doesn't contain substantial new information, is gratuitously baity, or is mostly fuel for internet drama). None of that is the case here—quite the opposite. This is just the sort of article we should welcome, so we can have substantive discussions about relevant issues instead of hurling the same old nasty platitudes at each other yet again. (Can a platitude be nasty? or do I need a different word?)
A thousand thank-yous to the user who took the time to email about this while the thread was still fresh; I wasn't focused on the HN front page just then, but I got the heads-up. If you ever want to make a big difference to HN quality, emailing hn@ycombinator.com when you notice solid, substantive content not getting the attention it deserves (whether because of flags or for any other reason) is one of the highest-leverage contributions you can make!