Exactly. There are countless epic threads that would not exist if people could delete their own threads. If you do make something on accident or need it moved/deleted, you just ask a mod. And if you want a thread deleted because you unknowingly pwn3d yourself, well good luck because history is not on your side.
Before posting, please ask yourself, "Will this thread/post/picture/comment/etc. better the NS community?" If the answer is no, DON'T POST.
*Boycotting NSG since 11/4/10*