Some (probably not original) thoughts about originality

"[B]eing the contrary person I am I started wondering why [OA journals are not willing to publish articles already published elsewhere, or why they follow the Ingelfinger rule]. For a commercial publisher with a subscripton business model it is clear that you don’t want to take on content that you can’t exert a copyright over, but for a non-profit with a mission to bring science to wider audience does this really make sense? If the science is currently unaccessible and is of appropriate quality for a given journal and the authors are willing to pay the costs to bring it to a wider public, why is this not allowed?"