Nothing imo, it's historic facts. But what is wrong imo is using the situation for PR purpose.
No one who actually cared about not glorifying the Confederacy would continue to sell Gone with the Wind, as Apple is doing.
It's important for gestures like this to happen to fight against the growing threat of 'social justice' fueled censorship. There's a big difference between not selling to people who want to wave the battle flag to trying to erase every depiction regardless of context. Standing up against such foolishness is important.
Be clear that you are not implying Valve is doing this without offering any proof.
Also, what is your opinion on Apple using the shooting in Charleston for PR purpose?