Stalin died less than a decade after the soviets' incredible victory against the nazis, which made him loved by a ton of people. And then the party decided to undo everything he did? You could debate whether stalin was good or bad, but my question is what made the party switch directions after stalin died?
Increasing paranoia as a possible result of his stroke led to a pretty major increase in people in the gulags and Stalin's own distrust of everyone right before his death. Take the Doctor's plot for example. In the last years of his life he was starting to act rashly as a possible consequence of the stroke he suffered, and that kinda proves it. As a result Krushchev was pretty willing to go back on a lot of stalin's final moves regardless of whether they were good or not. There were still staunch stalinists in the party like molotov but the big names, including corn boy, managed to put them out of power to shift the direction of the soviet union.