I think that the website must have some new communities in "piquant" topics to survive (to become enough well-known and contributed in the next say, 50 years).
"piquant" topics would be in my opinion (just examples, no connection to existing site proposals):
* Cosmetics
* Chemistry
* Biology
* Finance
* Accounting
The last website added to the network is about tabletop games and barely has any posts in it (it doesn't have a pager); I think it was a too of a "niche" choice and the owners of the network should actively seek website ideas in fields that **may** be less interesting for them personally.
The aims for this post are to:
1. Suggesting to community managers to consider replacing the current mechanism for community proposal (for example, allow just one person to start a community given relevant background in the field and in moderation)
1. Suggesting to community members to further emphasis non niche topics so to prefer creating communities primarily on general audience topics