The founders of SO had a theory, that irrelevant noise was what drove a site into insignificance over time. Even if it was just polite chit-chat. They took pains to automate out as much as they could, and put in place a culture that actively discouraged and removed it when possible. That culture remains even though the founders are long gone.
The founders left, and it went downhill as a result.
I think I replied to you earlier about it, but to reiterate: the site was going downhill for years before the founders left, and there is abundant evidence that the founders wanted exactly what mark-r claims.