The nomenklatura and the appartchiks of the party bureaucracies ossified into their familiar forms not from 'power madness' but rather in reaction to British, American and French efforts to return China, Vietnam, Russia, Cuba, etc back to the control of their landed or gangster overlords.
Stalin, Castro and Mao were authoritarians, certainly. And the critiques of their regimes offered by other Marxists (Luxemburg, Pannekoek, Goldman et al) were valid and timely, but it is too simple by degrees to reduce the revolutionary stall to power hunger.
The West, collectively, poured untold bodies and treasure into counterrevolution, and this forced the much poorer and less capitalized Marxist governments into defensive industrialization and armament.