I don't see anyone in this thread suggesting we should sweep this music history under the rug.
But I do see the argument that minstrel music should be performed by whites "because its a good tune" as being the rough equivalent of telling a racist joke, and then saying "I was only kidding, I didn't mean any harm by it".
If people choose to perform these songs, they should be prepared for some serious criticism by people who are offended by them, IMO. As it should be.