Since I can't think of a sarcastic comment I'll point out a slight flaw with your proposal.
People complain for two reasons:-
1. They want their complaint to be heard by those it is directed at.
2. They just need to vent due to frustration.
If a specific 'moan section' is set up people will probably assume that anything they post in there will just get ignored by SI so those who complain due to reason 1 will probably end up posting it in the General Discussion area anyway to reach a wider audience.
Personally I think the 'What's getting my goat:Non specific whinges...' thread that Jimbokav1971 started should be stickied.
Just my 2 cents