But he never stepped down or reformed the system to account for these issues. Hence my opinion of him.
I didn't see your edit: I guess my point is Stalin did not act under socialism, or surely not in an environment where corruption, if not coming from necessity, would hinder or be neutral to one growth within society.
I already mentioned that trying to resign and being met with unanimous rejection doesn't say much, other than possibly the obvious fact that he was in fact a human and not a robot.
To reform the system he could have rejected the idea of a single head of state in favor of a shared position, he could have set up the lenght of time by which a person can be head of state...
The possibilities are endless and history has made this kind of necessities abundandly clear to guarantee decision makers hold their position selflessly.