I have been in and out of freelancer since it came out (2003). I have always enjoyed the creativity and stories that players have driven the enjoyment of the game. I would like to start by mentioning creating new content or keeping things interesting is a genuinely difficult task that I appreciate the admins taking on.
Looking back on busier times the problem may be choice. Imagine you look at a bunch of sauce on a shelf and you have 100s of choices...what do you get? Do you take the time to try every thing- do you pick just one- do you give up and just leave? It's the endless choices on the server that may contribute to the decaying population. At the end of the day players want to play with others. As many have pointed out, when someone logs on you see 20 players maybe. Put 20 players in 3 systems- that's good interaction and RP. Now when I say "choice" it's left vague on purpose. There are many ways to limit "choice" with the objective of promoting player interaction. The first that comes to mind is factions. You could theoretically around 50 players that belong to 50 different factions, most of which may not even readily interact. Another problem may be the vastness of of the systems and sizes. Perhaps the problem lies in the limitation of RP depending on a combination of those factors or the limitations of the IDs (system/ship/combat restrictions).
I would suggest that "less is more" in the current state of things. The best experiences I have ever had on this server have been between only a few factions, the nomad revenge server used a 3 faction system of pirates, hunters, and traders. It promoted cooperation between each faction while allowing for flexibility of ship types, RP, and system roaming. I'm sure there are ways to create unification between factions that are redundant to allow people to interact more. My recent logging has gone like this: Log, look at population an system locations, realize there are like 20 players with only 3 belonging to the same factions, look how far away they are -log off. Best days go like: log on, attempt interaction, run out of RP because its 1 on 1,-log off.
When I first started playing freelancer multiplayer, I played on raw, an unmodded server as "Sajuuk" then the nomad revenge mod as "Sobek" then eventually landed here. I have always loved the expanding story, universe, and ship base. It saddens me that the server is slowly decaying. I remember having to wait to log in with over 100 players online at any time. I very much would love to see a creative idea or change to bring back those times. I don't know if those days will ever return, but I hope the community finds a way to revive itself. It would seem that the current path may be losing player interest.