I've seen threads pulled not because of the subject matter presented by the poster, but because they became magnets for offensive comments by others.
I remember one thread, a few years ago, that veered more and more off course - into fairly offensive language and metaphor - as it grew past 50 replys. Finally, the mods pulled it. The comment on the purple page was something like "I don't have time to babysit this thread."
No,it said for review, I guess I stepped on some admins relatives toes.....