Chris McDougall begins BORN TO RUN by describing how he's been hobbled--by his shoes, it turns out--and how the best running doc (Philly area??) tells him he's too damned big and should stop running altogether.
By the end of the book, he's completing 50+ mile races. Speed isn't really the point.
Like others, I'm not convinced that shoeless running, or Tarahumara sandals, or Vibram Fivefingers, is the way to lower world records--certainly not track records.
By the same token, very fast shoeless runners occasionally do show up. Bikila and Budd come immediately to mind. In 2003 or 2004, I remember seeing a barefoot female competitor in a Dallas-area Octoberfest 10K; she had beautiful form as she headed towards the finish line, bare feet whispering across the pavement. I think she was in the top 3 women. (Name, please?)
There's a dialectical process at work. The minimalist movement is simply a culture's way of pointing out that certain potentially key forms of knowledge have been ignored in a capital-driven drive for modernization and "progress." It's always good to pay attention when "crazy" people show up and...oh, I don't know...suggest that mainframe computers might be supplanted by individual desktop devices. Sometimes needed innovation looks a little kooky from the perspective of settled knowledge. The truth is usually somewhere in between.