Ok, I have to comment here. You can't deny that all these groups have been oppressed. I mentioned the Celtic culture earlier. I'm Scottish and I'm not offended by certain tropes BUT my culture isn't CURRENTLY being oppressed. So, I can understand if certain groups would be offended by images of colonialism and what-not while they are simultaneously being treated unfairly.
I don't think it's fair to say, "We experienced this and coped, so you should get over it."
You should say, "We experienced this and understand. Here's how we can help."
For the record, My issue on the Orc debate doesn't deal with this aspect of people's complaints but I've already been over that.