The reason for the seperate board is so that when people cause problems, we can remove their posting privelage in just the spoiler board without having to go through the whole process of warning and banning people from all of AP.
We can't do that with just a thread in the regular forum.
It gets really aggrivating deliberating over whether a person deserves a strike or a banishment over all the spoiler drama. We don't like banning people and it turns into kind of a long, bureauocratic process. This just saves a lot of headaches. It also SHOULD make people more conscious of what they post knowing that one little screw up and they're done with spoilers.
BTW if anyone has any questions about the rules, or if I didn't make something very clear (I was kind of tired when I typed them) then let me know.