I completely agree, history is not a safe space. If we're to prove any progress at all, it probably SHOULD be offensive. However, I don't think this is a new phenomenon at all. History seems to be one big spiral of rising and falling, revision and deconstruction; meaning, basically, that humanity as a whole seems incapable of truly learning from the past, no matter how much we as individuals might attempt to do so. I can't think of any group of people who has successfully avoided the pitfalls of their predecessors in a whole new way, without immediately falling into another pitfall they forgot to look out for.