Some people, like tsars, presidents, etc. have life by the balls. They make history but when they are gone, the history gives them such definitions as the terrible, the bloody, the awful. Human memory tries to erase them (Pinochet, Hitler, etc., ) like shameful blot.
Throughout the history of humankind, there have been examples of people who will never be forgotten, and their names are retained through the centuries to continue inspiring the others by their own examples (mother Theresa and others).