Page's misuse of Haldane's Dilemma

I think that what they mean by most mutation being beneficial is that scientists believe that every part of our being is the result of a mutation of some kind. For instance,microbes,which according to scientists are our most distant ancestors,had no eyes per say. We developed eyes as we evolved...same thing for hands,feet,teeth and so on. Viewed in that light,we can conclude that most mutation were befeficial to us,since we're all here.