This is exactly my point. Scrapers typically don't store cookies, so every single request is likely to be a "new" user as far as the forum software is concerned.

Couple that with 15 minute session times, and that could just be one entity scraping the forum at 30 requests per second. One scraper going moderately fast sounds far less bad than 29000 bots.

It still sounds excessive for a niche site, but I'd guess this is sporadic, or that the forum software has a page structure that traps scrapers accidentally, quite easy to do.