First, I can't take this woman seriously when she says "only Caucasians was free". That sure doesn't sound like proper English to me but I'm a little picky about that so...moving on.
Second, if we stopped teaching everything that was offensive to someone the history of the world would disappear completely. Maybe they think that will make it all better? To pretend it never happened?
Our children are already growing up to be way less intelligent than previous generations because of the way they are treated, disciplined and the information that schools are allowed to teach. Heaven forbid we teach them about the past, even the bad parts, so they aren't doomed to repeat them.