Well, from the top forum on the list (Newcomers), "Please Read! The Newcomers Forum is a safe and welcoming place for newcomers. Respect is essential. Debates over Recovery Methods are not allowed on the Newcomer's Forum. Posts that violate this rule will be removed without notice. (Support and experience only please.)" The "rules" are more relaxed in other forums, but the site owner and mods apparently think it's important.
I think it's not about treating newcomers like children, it's about not given them the impression that we all are bickering children - which will make it more likely they'll leave, and not get anything positive from the site that might help them.