I haven't got the impression that anyone on GN is saying, or even implying, that they know better than "the scientists". Some scientists are saying a, b, and c; other scientists are saying x, y, and z. In the noble tradition of debate within the rigours of the scientific method, things are still being hammered out that are not fully understood yet. I think it's quite exciting, especially as new things are being discovered that incrementally increase understanding all the time 