"every Confederate soldier ... were ... American soldiers. [editors note: false] That is reason enough to honor them." -- And even if someone is an American (like Timothy McVeigh, for example; he was an American), why would that alone be reason to honor them?
Furthermore, from an objective standpoint, racism is wrong, and Confederate statues were mostly created for racist reasons. Your idea that no one can have opinions (you are telling me I shouldn't have my opinion or express it about Confederate statues) is ignorant. So is your idea that objective reality doesn't exist. In fact, some arguments are better than others. Some are more moral than others. And there is no good argument for having Confederate statues up in the United States, a country that defeated the Confederates.
An MLK statue might be hated by racists, but actually it would be accepted and even supported by the vast majority of people. Because we have a culture that mostly frowns on racism and mostly supports equal rights. You cannot ignore our culture.
Yeah, we should tear down MLK's statue for... ...what?... ...having an affair?...
If you want to make an argument for why it is an outrage to tear down Lee's statue, go ahead and make it. Instead you are trying to make an argument for a different proposition.
In fact, there is no good reason to tear down MLK's or George Washington's statue, and it is hard to imagine in the future a large amount of Americans will think it is a good idea--and if they did, they would be wrong, and I would argue against them. Just because people tear down Lee's statue for completely different reasons doesn't make it any more likely that they will tear down MLK's statue when a completely different argument would have to apply.