I think the Jedi were the most powerfull organization at one point, but for various reasons had a fall from grace. At least, that's what I think the PT was trying to tell us, albiet very poorly. Again, I think the point of the PT, at least regarding the jedi, is that although they are/were the most powerfull beings, they are fallable. However, the problem with the PT, IMO, is that they made them too fallable without giving us a point of reference as to where they started from.
I think the PT would have been much more affective if it had better illustrated to us how or why the Jedi were loosing their way.