On one hand I understand that deleting the unpleasant and offtopic posts creates the comfy atmosphere for idle chitchat.
On the other hand every time the issue comes up it will be full of confusion. For example how easy could have been for me to type: "member when I had to create a thread?" and the NEETs would member, or even search it in the catalog. But now its memoryholed and those who didn't pay attention or were boonged don't know what's going on and I have to use tiresome walls of texts of explanations.