While Randy has issued his ruling, and an important commentary on the role and functioning of moderators, I think the rationale behind the rule has been very ably expressed by Sebastien and PremEx (and saved me from trying to take a stab at it).
As Flyer Talk grows in size, it becomes more important for information to be logically organized so anyone can find it, and participate.
Issues like informative thread topic titles, subject-related posts, and posting in the proper forum, become ever more important.
What kind of a library would you have if everyone decided where to shelve their books, or even circulated petitions on their view of the best way to organize the collection?
If the library analogy fails, try this. Adhering to organization and the simple rules to maintain it is really about courtesy and manners. It is about respect for the thousands of posters who wade through posts daily. It is about consideration for your fellow Flyer Talkers' time!
Anyone seeking or offering a UA coupon can easily do so with the help of the "search" function. An offeror seeking only a "loyal UA flyer" can do a simple search of the airline forum in question of the posts by that would-be-recipient. I suspect that those who would "take the law into their own hands" are not taking full advantage of the wonderful capabilities offered by that search function.