They both came from the earlier `cvs annotate` command. annotate is the original name (from 1996). While it was common to talk about cvs annotate as 'blame', I think it first became the name of a command in subversion 0.32.0 (~2003, rcs blame was ~2004, cvs annotate grew the blame alias ~2008)
These days I mostly use IDEA's annotate feature and don't even know what's the command used in the backend.