So then the problem arises when you have a statue of a King, Queen, Emperor, Conquer, Religious leader, Military Commander, President, Discoverer, Mountain man, etc. because they lived in a time wherein they shared the era's dubious values regarding family, sexuality, human rights, women's rights, religion, democracy, torture, war, slavery, etc.?
The present cannot dictate the past; what we can do is honor history and recognize those who represent the significant, the relevant, the memorable. A statue of Robert E. Lee no more represents slavery than a statue of the Tudor Queen Elizbeth represents the divine rights of royals or a statue of Martin Luthor represents the cause of anti-Semitism. They are acknowledged because each, in there own way, were unique and powerful agents of history who usually, in some manner, different than their contemporaries.
And it is that uniqueness and importance that provides the bridge to a people's history, the mystic cords of memory that bind into identity.