There’s an antipattern that Internet social sites tend to: people get nostalgic for the old times, and think that if they can just get rid of these annoying newcomers they’ll get the old site back again just like they remember.
This never works.
The primary fallacy is that the reason it was interesting back then was that nobody knew what they were doing and what would come next; attempting to encase that in carbonite is unlikely to achieve the desired effect. The secondary fallacy is that they themselves are different people now.
(I’m thinking of two sites I frequent — RationalWiki and LessWrong — going through precisely this angst right now. And of another, where a Usenet newsgroup from 15 years ago just revived itself on Facebook, and it appears to be working precisely because we’re different people now so it’s interesting again and we don’t know what happens next.)
“RETURN TO THE MISSION WILL CURE ALL” just won’t work out like you think it will. All communities have a life cycle and will die; recovering yours will be at least as uncertain as striking out with it originally was.