At the end of the day all you need is one person and one bullet, right? See: JFK, Indira Gandhi, John Lennon, many more. 50,000 people all with a lot of bullets seems like a bit of a problem no matter what. Gandhi in particular is interesting, as she was murdered by two of her Sikh bodyguards angry over how she dealt with the Sikh independence movement at the time. Who knows who will get "inspired" from this action, and what they will do.
Learn from the past. Assassinating the dictator just creates a power vacuum that someone else fills. Look at Iraq. The US killed Osama Bin Laden. Then Al Qaeda. Now there’s ISUS and they control everything there. Figure out what will fill the power vacuum or you may do more harm than good.
Counter-examples: Hitler, Mussolini, Pinochet, Fujimori, Franco, Nigerian dictatorships, Taiwan, and probably a few more. Not all were "assassinated", but countries really can transition to something better.
"Learn from the past" doesn't mean "look at this one example where things went wrong and then never do anything even remotely like that ever again".
