Uh, they don't fund the research, they don't pay the reviewers, and they charge money to publish. They provide exact formatting rules and documents for all submissions, and reject if improperly formatted.

I'm not sure where you get this idea that they are doing any significant typesetting, or that their administrative costs are anything remotely reasonable - even the journal editors are also largely unpaid (because being the editor of a journal can be helpful when trying to get a job in academia).