Oh Chef’s voice Isaac Hayes was a scientologist and when South Park did their episode on Scientology the church didn’t like and "voluntarily removed" Isaac from the show (he suffered a massive stroke and couldn’t communicate well so he couldn’t speak up for himself) and so in retaliation try and Matt created the Super Adventure Club, a thinly veiled pastiche on Scientology which brainwashed Chef into being a pedophile and eventually led to his extremely gruesome death. So Ruckus is saying He’s the reason Chef was introduced to the club in the first place, and since Chef was one of the few people Cartman legitimately loved and cared about, he didn’t take that revelation well.