Barefoot Running

[Susan]

I get the point that it is wrong to believe that barefoot running will magically prevent injuries and that some problems will be more common in barefoot runners (PF) than in shod ones.

I don't however get why anyone, especially a scientist, would come to the believe that most humans where not made to walk or run without shoes. The author of the article compares shoes with wearing glasses. He would have a point here, but would anyone believe, that because there are humans that need glasses, human eyes generally were not made to be used without them?
Also, how can we know if the problems caused by barefoot running in new barefoot runners aren't caused by the fact that most of us are used to wearing shoes all our life, from early childhood on?

A really neutral scientific discussion about barefoot running seems to be difficult because a lot of "believe" seems to come into play when ever it is discussed.