Typically, if the post is positive, the question of comment will stay. If you or someone else is bashing another user, though, then it will be removed. The site doesn't want members to be spoken about negatively.
Generally, something must be reported by a user to bring it to the attention of administrative staff. Things that are not reported are far less likely to be removed.
Members are not allowed to post questions, opinions, replies, comments, etc. that are insulting, derogatory, or offensive to other G@G members. What constitutes "insulting, derogatory, or offensive" is rather subjective, so the decision ultimately depends on the administrative staff reviewing a report.
the admins may reinstate the question you made. Mods are human too. They can make mistakes. In terms of why GirlScout left, she told me she left because she was getting tired of getting into arguments with annoying people on here.