The only thing worse than being a BIG part of history (albeit as a loser) is being a small part of the winner's narrative that you were a decent guy who just couldn't cut it. Meanwhile, everyone kind of knows something else it up but just can't breach the fog of war, so we're just left with a disgusted face about that person despite his now small footnote in history. The legacy of actually being a really good bad guy gets erased, which is maybe more important than actually getting taken out except for maybe some process crimes. The pathetic-enemy narrative crushes their prideful soul. No one will read the autobiography. Even if some do, they'll doubt it.