I have a blue name which means i am a mod which means S+M is my forum. I can decide what goes inside that forum and can full well decide what warrants delete and what doesnt or i wouldnt of been modded (im trusted with that responsibility).
Actually you are wrong on this one, mods on any forums can delete messages and they do, its just that this forum lets members see deleted posts where as, on other forums you cannot see them.
And your point about memebers being able to decide what they want deleted from their own thread is a doubled edged sword, what happens if someone is new to battling ? and then someone gives bad advice and they take it. They are only getting hurt by this advice.