I think it's silly to assume that just because certain "power users" sometimes post inane content on reddit, they are not capable of any serious discussion on here.
While I concur that they may be more than capable of participating in serious discussion, I'm just not sure they want to. They yearn for that instant gratification they receive when they see their inane comments receive attention. The faster they put forth their garbage, the more attention they get. If they were to attempt to add quality content, it would severely slow down the highs they feed off of.
I concur. I still haven't seen the Navy Seals copypasta here.
Perhaps so, perhaps not. Time will tell. The pattern on Reddit was that there was often shenanigans going on that made power users... well, power users. Scopolamina used alt accounts to vote up his stuff and make it more visible, Trapped in Reddit used a comment-recycler bot to gain immense amounts of karma, and a rat-pack of popular users had a "rising threads" private subreddit where bots tracked where the most likely spot to post a comment would gain upvotes. I wouldn't say they're not capable, but considering the case of Karmanaut ( a rather long tale where no one really won or did anything but people are still pissed for whatever reason to this day) and other similar users, it seems like a lot of them wouldn't fit in over here.