I'm not going to pontificate on it for the same reason, but I'd also say that it's not really clear what exactly the standards are for "too <whatever> to be post count worthy," because it seems that it's a standard that only applies to OT serial threads and not to other kinds of questionably "too bloggy" type threads or "serial" threads, particularly in the other Colosseum subforums- as an example, the "Questions not worth their own question thread" threads in OT do get archived, but the Computer Talk and World History subforums also have "Questions not worth their own question thread" threads that are just about questions specific to that subforum's subject, which don't get the same treatment, even though there's not that big of a difference between these thread types. Humor and Jokes is made almost entirely of serial threads, a lot of which are mainly dedicated to just posting pictures of things. Hell, there's even other serial threads in OT that don't get archived, I guess because something like the Clown Car threads on general goings-on in politics are about a less random or more serious subject than some of the ones that do get archived? Hell, I'm sure if I looked around I could find non-serial threads that are still kind of bloggy in their discussion, or even threads in the main Civ Forums that aren't reaching any kind of quality level of discussion.
Which again, is not to say any of those posts are less worthy or unworthy compared to the Random Rants or What Music Are You Listening To threads, they're all contributing things and better discussions than you'd think in their own ways. I'm certainly not arguing that say, the Funnniest Pictures threads in Humor and Jokes having postcount is a bad thing, I think the serial threads in Humor and Jokes absolutely should have postcount.
I'm just pointing out that I can't see exactly what set of standards are specifically excluding this particular subset of serial threads in Off-Topic, and honestly, I don't really think you can come up with a truly fair standard for what "should" and "shouldn't" count for postcount (aside from spam or other rule-breaking) because the actual threads people make don't really always fit neatly into whatever categories and dividers you're using, so given all that, why not just let everyone keep their postcount, and count every post in every thread everywhere on the site the same, as long as the post doesn't break the forum rules?