There have been complaints due to the 'immaturity of certain mods', so the jokes have (generally) stopped. People just don't appreciate them.
As for thread locks, it's often not only because of potential (or realised) flame wars, but quite simply due to the fact that different people tend to create 9+ threads on the same subject, especially when a news post comes up. As well as that, if it's news someone percieves as negative (let's face it, that happens pretty much every time) there's a strong potential of having flame wars in all those 9+ threads.