I do agree that self-promotion can pose an issue. Every passionate developer has been at the point where they try to plug their game all over the place - it's natural for something you put so much time into!
If people want to advertise, they can keep a running devblog and update it in another section of the forum. If a game is being featured weekly, it should be moderator chosen with no applicant process. And the focus of discussion should be on its design and how it might be improved. There's no perfect game, and hearing good constructive feedback can have a positive impact on the developer.