We have to remember the incredibly difficult conditions that confronted genuine scientific work in the Stalinist USSR, quite apart from the fact of total isolation from the West and desperate poverty and social crisis.
Now, when the Bolsheviks came to power it became very fashionable, so to speak, to apply Marxism to any particular branch of activity. This generally involved whipping a few quotes out of the classics of Marxism, particularly Anti-Duhring or Dialectics of Nature and demonstrating that this or that line was in accordance with the precepts of Communism.
The whole period of Vygotskys professional life was a period of intense factional strife in the Soviet Union, and in particular the period during which Stalin established absolute power within the USSR.
Under these conditions, scientific debate, or any other kind of debate for that matter, became extremely difficult.