However, the line has to be drawn somewhere.
This reminds me of King Stannis's opposition to including drugs in D&D. IMO, the issue is a conundrum, so to think it through...
I can understand viewing inclusion of real world horrors into a game as being in bad taste in the same way as telling a joke about slavery could be construed as being in bad taste, but beyond that...? Far worse horrors are in novels and movies, yet they are an accepted part of our culture.
The mental hurdle seems to be that popular media can cover slavery, prostitution and drugs, but not an RPG, because it is different. Different, how?
I think the perceived difference is twofold:
The first problem is, IMO, in the idea of "playing a game" with the idea. By definition, including such things in a game is for reasons of creating "fun". But, the thinking must go, these things aren't trivial and are abominable rather than fun, and they are made trivial and turned into a source of fun by inclusion in a game.
The second problem I see is that we trust the popular media to treat the subjects with a certain minimum level of respect - there are publishers and censors to enforce this. In a game, there's no-one to stop you from mocking or trivialising the issue, or even revelling in it. The fear is that it will influence people's perceptions of the issue - maybe even turn them "evil".
But then again, we trust irresponsible people with "evil" subject matter (such as movies about murder) from popular culture, don't we? To have a different rule for RPGs is to state that RPGs are different, and are potentially more harmful than books and movies. Given that all three rely upon a world in the imagination, the only difference seems to be between playing a character versus watching or reading about a character. I'd hesitate to suggest that the difference is meaningful, but it could be.
A complex issue.