I don't really care about post count and it makes sense for it to be taken away from the contest section.
The "you can only hold one contest at a time" rule was implemented because at least one person (possibly more) would hold 4-5 silly, super quick, spammy contests at once. I remember it well. I was upset at the time because most of us hadn't done anything wrong, and because of this stupid spammy person we could only hold one contest at a time now
The argument that "there aren't enough threads!" was made for the drama CD section, too, remember. (Was it the drama CD section? I remember Isan was involved, and it was before she was a mod, and she kept updating me on what was going on, but I wasn't actively involved myself.)
It's not really a big deal and seems everyone likes the idea. So, one sub-section for set contests, and one for all other contests. Not that hard XD