With the addition of a sub forum, activity would increase since intelligent threads that aren't really in debate format are thrown in General Discussion would be placed in SFA instead.
It would be difficult to moderate both types of threads in one section with the "strict rules" sticky in place, which is why I suggested a new section.
As others have stated, "intelligent discussion" isn't limited to debates.
Most threads created in General Discussion turn into debates, and most threads created in SFA are often moved to General Discussion because of the "strict rules" sticky. These threads are interchangeable and can go both ways. Wouldn't make much sense to keep these threads in separate forums.
The problem here is the "strict rules" sticky more than anything else.