To answer the OP - it is simply less time consuming to pre-moderate the debate than deal with the fallout of it being unmoderated (which cost us untold hours and several forum members). It also means that we don't have to exclude anyone, making it
more inclusive than permanently removing people from the discussion whose only "crime" is to be extremely passionate for
their side of the debate.
A positive side effect of the pre-moderation has been improved quality of debate and increased substance for many of the posts.
It is as open for new posts and threads as it always has been, you just might have to wait a little while for a moderator to approve your post(s); but as it's not a time-critical issue that shouldn't be a problem.
Cheers,
Shaun