Tankies are people that defend or deny the shitty things done by ML states. People can appreciate some of Lenin’s ideas, but not defend the states inspired by his ideology. The Bolsheviks under Lenin set the groundwork for Stalin’s reign, with many of Stalin’s terrible practices being inspired by things Lenin did. Lenin crushed opposition and centralized power while he was in charge, with Stalin doing what Lenin demonstrated to be acceptable behavior for their movement. When you reject the results of democratic processes to gain power, don’t be surprised when your successor does the same. One can agree with many of Lenin’s ideas, so long as they recognize the weaknesses.