No one wants to engage in what basically amounts to Pokemon small talk--just look at some of the "discussions" that amount to posts like "offense is my favorite style" or "dragons rule!" They fill space in a forum that resembles a former heavyweight champion now in his seventies living off of social security, but does anyone actually enjoy these things or get anything out of them?
Just saying, those are polls; most forums have them, including pretty much every one of PC's forums. I agree that it would be nice to have more in-depth discussions, but I'm not sure when the community is ready for that. For one thing, discussions like those have never been very active or successful, even back in the S&M days. But you never know until you try.
As for DCCs, I was never a big fan of them, especially in BC. For one, it takes away activity from the rest of the forum unless the forum is focused on off-topic discussion (like CC&P), and discussions with a topic tend to have more direction and activity. For example, a general metagame discussion on XY OU would be fine because there's at least something to keep discussion based on, rather than simply telling everyone to talk about battling (which didn't work that one short time I made a DCC). Also, I've been wanting to do a sort of XY battling club that's geared around trying out XY OU, finding new strategies in it, helping each other get adjusted to the new metagame, and just getting involved in maturing the metagame. There would be more stuff of course, but that's just general idea.
Annual battling events could work. I've tried many "major" tournaments in the past, but they usually fail. The closest I've gotten to making them work is the Randbats version of the PC League. However, it lasted too long and some users ended up inactive after so long, along with the fact that I didn't bug people about the last round via PM (which makes a
big difference, by the way). It's important not to rely on individual users for too long like a typical league, and expect the worst to happen but hope for the best. I may start planning a UU tournament sometime soon, as I've been wanting to do one for a while now.