Yes, I think this conflation stems from a misunderstanding of orthodox/classical Marxist theory (and/or Lenin's ideas), a misunderstanding, it seems, shared even by remarkably disparate schools of thought:
"Although the 1920s were marked by some degree of variety in historical inquiry [within the USSR], this finally ended with the tightening of Joseph Stalin's hold on authority. [M.N.] Pokrovskii died before this could happen, and by the mid-1930s his works were being attacked by his own former pupils. Stalinists claimed that Pokrovskii ... overstated the importance of material development --- that he was an economic determinist ..." Jeremy Black & Donald M. McRaild, 1997, _Studying History_ Macmillan: 65-66.