As a maintainer, maintaining is the hard part. The trick is that new maintainers will come from the userbase, and without making an install a matter of "aptitude install mediagoblin" or "guix package -i mediagoblin" followed by a short config file edit, the userbase will remain small.

It might be a function of the languages/frameworks chosen, but without that level of engagement it will be difficult to grow (and thus encourage others to help make things easier).