Hi there @TheBossOfMe . Thanks for getting in touch.
We do try not to delete entire threads on Mumsnet where possible. We don't mind individual posts going so much as long as it doesn't interfere with the flow of the thread. However, we do make exceptions sometimes.
If a thread is likely to affect someone in real life, whether that's because they've been identified, or the thread might affect their family members or job, or simply because it's causing them undue distress, we will remove it. We take each request on a case-by-case basis and where possible will offer other alternatives such as making some edits to a thread or moving it to somewhere quieter. But we don't want to make anyone's lives more difficult than they already are; that's just not what we're about.
So there's usually a lot more to it than someone just finding the posts upsetting or people not agreeing with an OP, and rest assured it's not a decision we take without a lot of thought.