Although EBM (at least in its popular application) cannot evaluate the unscientific claims of CAM (you need SBM to do that) it is useful for evaluation of most of the clinical questions that arise in mainstream practice. And I wonder what David Sackett would say if asked about EBM's blind spot. Right off the bat in the interview below he swats away some of the concerns of EBM's detractors by saying that first and foremost it's about the patient and clinical expertise. It's these elements that must be combined with the “best external evidence.”
His review of EBM's history is interesting. The movement had its antecedents in the 1960s with the birth of the discipline of clinical epidemiology at McMaster University.