Wasn't Napoleon much better than Robespierre? And frankly even the Louis?
Discussion
I'm not sure I agree that it was good to depose Louis XVI; if you must have a government, monarchy may actually be preferable (see Hans-Hermann Hoppe, "Democracy: The God that Failed," and "From Aristocracy to Monarchy to Democracy."
Perhaps Napoleon is being called worse than Louis for the bloodshed and devastation he unleashed on Europe.