I think a lot of it might stem from Livejournal randomly deleting a bunch of everyone's stuff back in ... 2007? I'm not sure exactly, but I know a LOOOOT of people got very paranoid and started banning sex logs from games even if under a cut and posted with a warning where they still have the option to read it, because the mentality was all that it would take is one disgruntled player or parent reporting the game as posting that type of thing when minors had access. Also, many games started requiring players to be of age/requiring birthdays be made visible so even if a minor was lying to say they were older, it would be because they deceived the moderators etc. I'm not sure if it's such a huge issue now but it's one reason I could think of as to why people would be uncomfortable with this type of thing in a game where minors are present.