"Oh, you know, outside of his support for the enslavement of human beings, he was totes an honorable dude!"
Nobody wants to erase history, people would just rather not honor and look back on some of the worst atrocities in American history with rose tinted glasses. You know what group of people are interested in erasing history? Those who insist that the Civil War was fought over states rights, government overreach, or any other bullshit that wasn't slavery. Never mind the fact that the state of Texas has been sanitizing its curriculum on slavery, going so far as to imply that the slaves were simply just migrant workers; or the fact that those confederate monuments were originally commissioned in the 1950s, almost a full century after the Civil War took place.
Statues and flags do not provide a window into the past, history books do!