The key point is that humans (including humans from the past) are imperfect beings. They do good and they do bad.
We remember them, generally, for the good they do.
If someone points out that MLK was a philandering plagiarist, I would say, "Ultimately, that doesn't matter. That is not why we celebrate his memory." We honor his memory because of the "I Have a Dream" speech, because of the Selma March, because of his "Letter from a Birmingham Jail," etc. When someone points out his failings, we should weigh them in the balance with his achievements, and if the latter outweigh the former (which, in MLK's case, they do), then he should be remembered fondly.
And nobody celebrates Abraham Lincoln because he undermined the Constitution or suppressed democracy in eleven states, but because he was a great orator and did what he could to stop the spread of slavery and he kept the Union together. (In my view, the Union of these states is a morally ambivalent concept). While I believe it is worth bearing in mind that what he did was not exactly democratic, and he was not exactly scrupulous in his regard for the provisions of the Constitution, I also understand that those who honor his memory do because of his virtues, and despite his failings.
I would just like the same consideration for men like Lee. He was a great soldier guided by a tremendous sense of duty (just because you do not believe in the sovereignty of the peoples of the state does not means he did not believe in it), a gentleman (in the best sense of that term), a leader in post-war reconciliation.
When you come in here throwing around the word "traitor," I see two things. First, it is decidedly ungenerous. Second, you have a lot to learn about the history of your country.
