Is leftist history's treatment of Leon Trotsky the man unfair?

Disclaimer: I'm not going to pretend to know too much about Trotsky and his history and I'm certainly not going to come to the defense of Trotskyists, we all know they're the last breed of leftists this world needs. And I'm sure we're well aware of Trotsky's personal failings, of him being an annoying, know-it-all contrarian douche.

But at the end of the day, Trotsky was a revolutionary to the bone and one of the most influential in modern human history. One could say he is one of the founding fathers of the Soviet Union. As misguided as he may have been, he dedicated his life to communism in the Soviet Union. And yet, his name was tarnished and maligned in the Soviet History books. Stalin intense hatred of Trotsky drove him to murder the man. Trotky's assassin, Ramon Mercader, was awarded the title of the Hero of the Soviet Union. I mean, damn dude, that's a bit much, right? And throughout all of Khrushev's dumbass de-Stalinization efforts, Trotsky was one of the few Soviets whose name was never rehabilitated.

All I'm asking is are we too harsh on Trotsky and do we judge him too harshly based on the actions of his followers? Do you think Lenin would agree with Stalin's treatment of Trotsky and with communist history's treatment of him?