Myself and one other player (the dm's girlfriend) deliberately got ourselves captured by an evil empire to infiltrate and liberate a concentration camp. What we knew before getting ourselves captured was that they have been taking away anyone without their "papers" and people of certain races, including the other player's race. When we got there all of the prison guards were really nice and the prisoners were totally fine. One of them legitimately said that it was good to be away from the bigotry outside of the concentration camp. At this point we stopped the session, yelled at the dm and got him to agree to rewrite this section. I dont know how anyone could possibly think this was ok.
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I've seen DMs (and writers in general) get stuck in a loop of subverting expectations whenever they notice they've built them up, because they've gotten it into their head that this is what good writing is. Also lots of DMs/writers only engage with history and ideology on a trope level - nazis are just when your evil empire cribs its aesthetic from Triumph Of The Will, not actual people that sucked with actual beliefs that sucked and actual power structures that sucked. Put them together and you get good nazis, what a tweeeest.
The only time I was in a session were "camps are good"(*) was used to subvert was when the people doing the guarding were former resistance people believing that the liberal peace with the enemy fascist/capitalist empire was good and wouldn't lead to harm (demilitarizing the revolutionary squads was part of the deal). Naturally the evil empire just got in with an army and killed everyone and was happy for the preparation done by the libs.
(*) and even then there was widespread abuse of power, also the reason for the camps was that only standing citizens (so powerful landowning families and their staff) would remain and thus Feudalism be restored outside of cities.