Great point. Once you look at history you realize that almost everybody in history was quite flawed in one way or another. Perhaps we really just have to emphasize what aspect of that person we are celebrating.
Allthough e.g. Winston Churchill was a pretty bad man, I think it is clear that nobody put up a statue of him to celebrate him ordering workers to be gunned down by the police or his role in cutting down Indians with cavalry charges, taking their food.
Perhaps statues should explicilty state WHAT about a person we celebrate, while we also mention the things they did which we don't celebrate.
And we should get more status of the forgotten people who deserve more reckognition. Statues of perhaps the defeated people. Maybe as Europeans we should also reckognize those that fought against us, but whom was model leaders for their own people.
Or how about the many women of history that was passed by? As a computer geek I would love to see a statue of Ada Lovelace e.g.