I think people like you way too often hear the word "offended" and imagine someone feeling a deep visceral and immediate uncomfortability with something.

That's usually not what most people mean exactly, though. Imagine if literally the only time your in-group was mentioned was to stereotype them. People know of your existence but not what you're actually like because it's been clouded with centuries of stereotypes. After a whole life experiencing this over and over and over you get annoyed and want to see other, actually realistic, representations, that's what this "offense" you mention is.

I mean, hell gamers and nerds get annoyed by stuff like Big Bang Theory, and that's sooooo much more trivial.