I've definitely noticed it with grand strategy games, take this with a grain of salt but I assume that it is because these kind of games let the players live their political fantasies, which I guess it's more appealing to people who want a different kind of society than the one they live under IRL. This is all just speculation though.

I personally like these games precisely because of that reason, I like building up socialist countries in Victoria 3 because that's currently the only way for me to "have a taste" of socialism, even when it's just a bunch of pixels on screen.