Quality and quantity are both important, because "quantity makes quality".
I don't agree with you on this and I don't think quantity actually makes for quality as I've seen very short post that contained Alot of quality and even earned Alot of merits as a show of appreciation for it's quality.
From a campaign perspective, quantity is important, you must create 25 posts every week to be considered qualified
From a merit perspective, quality is important
The two must work together, it's useless if you only make quality posts once a week.