This is exactly what ORCID tries to achieve:
ORCID is a nonprofit organization helping create a world in which all who participate in research, scholarship and innovation are uniquely identified and connected to their contributions and affiliations, across disciplines, borders, and time. (from their website)
However, not everybody is aware of this initiative or cares enough to set up an ORCID for themselves. Some journals requirerequest ORCIDs upon submission, e.g. for Nature Methods each Corresponding authors needs to have an ORCID. The problem with using other information to identify researcher, is that this information can change as opposed to a uniquely assigned number.