Gentlemen... To give you some ideas of more or less what's happened here recently with the player population in general for Freelancer I'd say there are a few contributing factors, some more recent, some more long-term but most of which are already mentioned.
Recent factors:
1. Release of Diablo III.
I don't know much about what other games you guys play on PC, but I know this is a HUGE franchise and a long-running for Blizzard in the PC world. Hell the Diablo Battle Chest set is still holding it's value even after some 8-9 years after it's release if that tells you anything! Me personally, I'd love to jump on it right now, but I don't have even the minimum requirements to run it at the moment.
2. World-wide economic problems.
I'm not sure how hard this is hitting most people and their families in certain geographical areas, but it's bad news for all anyway you slice it. It's a serious and very troubling situation, especially in Europe where it's the worst it seems...
3. Aging player base.
Pretty self-explanatory. We certainly ain't getting any younger and as mentioned, life priorities change dramatically for most as we enter adulthood. I saw this first-hand recently with the departure of Sam, callsign ARROW, as CO of the Silver Arrows when he recently got married in real life.(his new wife has alot to do with this I'm afraid) As a result, to my understanding Forlon is now Deputy CO of the Silver Arrows indefinitely, unless for some rare chance Sam returns.
Long-term factors:
1. Freelancer was released on March 4, 2003.
As incredible as the game was and still is IMHO, it's approaching 10 years(!) old. This is ANCIENT in the video gaming market these days and even more so in the PC gaming world. The only way this game is going to live on is the hope that OP will polish and release the new FL styled engine he recently showcased that can reuse FL assets and files and has a newer, more modern DX10 or DX11 type game engine. With the ability to use much more modern features and putting the engine back in the hands of capable independent developers within the FL community,(and out of M$'s damn greedy ass hands) the game could last indefinitely as one of the best PC space sims ever!
2. Fracturing of the Freelancer community with the past demise of the Lancer's Reactor.
The fallout of the Lancers Reactor's demise years ago and splitting up of the player base into separate communities will eventually DOOM this game into obscurity if things do not change. Granted, OP has restored that to some degree with hosting of LR on the SWAT Portal and hopefully as a peace offering to the other communities... But still much more needs to be done to unite the entire community even though I have very few ideas of how to do that effectively, as I feel there are still deep seeded feelings against OP and the SWAT Portal in The Starport community.
3. Long-term FL mod developer motivation and shrinking FL player base
This is unfortunately a secondary condition of long-term problem #1 which exacerbates it as well. As Gibbon has correctly pointed out, a shrinking player base due to the age of the game in general will only in the end add to the frustration of most FL modders. With no players to test their mods, no players to populate the server and no players to make it worthwhile pursuing further FL modding as a result, most FL modders will eventually lose interest and move on from Freelancer.
Anyway, there's most of them in a nutshell from my viewpoint, I'm sure others will add to it or expound on it as well. Regardless, the situation is most troubling and without any easy solution I'm afraid folks. I always hope and pray for the best though as this game is IMHO one of the best space sims ever made and I'll still even after 20 years from now want to crank this up and play it in single player, even if it's for nostalgia.