In Stalin’s era, left referred mostly to pro-worker policies, the economic change of the communist revolution. That convention was solidified in the US during the red scare, where left-wing came to mean “commie heresy.”

After that period, the definition was gradually blurred again, perhaps by conservatives carrying forth the McCarthyist tradition of lumping any non-conformist view into “commie heresy.” Regardless, the resulting confusion in public political discourse is the reason Wayne Brittenden made the Political Compass website in 2001.

By canonizing the economic-policy definition used by the Bolsheviks/McCarthyists as an actual X-axis spectrum, and the social-policy definitions of most other contexts as a Y-axis spectrum, one could easily map both dimensions as a cartesian coordinate. Quite handy.

Still, as elegant and illuminating as that solution is, it remains a convention.