I think a big reason that people get less feedback on scenarios is that the Repository is pretty much a mess. I never know where to get new scenarios, and even if I find one you never know if you should comment there or go on the forum.
I think a key to keeping the community alive would be the following:
1. Restructure the Repsitory to make it easier for people to find mods and scenarios
2. The BF team includes new scenarios developed by the community in its patches. In addition, these patched should be a little easier for the community to find. Many of us know to look for patches, but there has to be a way for BF to notify all of the players that there is an updated version of their game available.
3. Figure out a way to browse scenarios directly from the game
I think 1 and 2 are the best options. The patches are already fairly sizable and adding in 10 community made scenarios could really expand the scope.