I'm sure you have. Stalin could be pretty hard on his buddy Hitler, too - especially after the big breakup. Your point being?
1) Stalin was pretty rough on those who disagreed with his viewpoints. His detractors were always 'malicious' or 'traitorous'. No one who disagreed with Stalin got off lightly.
2) Stalin was a one-way man. There was this one deal, this one perfect system, and that was the only way it was gonna be. You no like? We got a cot with your name on it in the gulag, comrade.
3) Stalin knew how to creatively forget certain inclement facts. He might remember exact figures on steel production in Omsk, but totally forget about some politically inexpedient issue or other.
I just call 'em as I see 'em, bub.
P.S. When it became expedient to do so, the Reds tossed the Iron Dude. Now Marxists cringe at any comparison to the 'old man'. Watch them do the same to that famous "state capitalist" pundit, Vlad Lenin.
You heard it here first, folks.