Saying that the game is dying is one of two things coming out:
1) A person's desire to make other people quit the game because they quit, for whatever reason (they got bored for example).
2) People getting panicky because they play during down-time or on holidays and don't see millions of servers full of players.
Probably #1 more often than not. They forget that while they might be sick of the game, others are completely happy with it and others are just discovering it for the first time.
As for #2, when 1.04 patch came out, it was spelled out that 1.04 would ONLY detect other 1.04 servers in its built in browser. So thousands of 1.02 and 1.03 games were ignored. So people freaked out and assumed the game was dying. Some people still play those older versions and you wouldn't know from just looking at your in-game browser.
Anyhow, if JK2 stops being #1 (or in the top 10 of games) who cares? That doesn't stop you from enjoying it. And you can always use bots to fill out your games if real players ever get scarce in the future. That's the beauty of it....
Single Player can't last forever and people do move on to other games if they get bored. That's why editing (which is just starting to take off) can help extend people's enjoyment of the game. But not everyone is aware of where to get good mods, and may have given up on the game already. But it's their loss... just enjoy what you have. ; )
So yes, technically if there is one less server every day than before, you could say it's "dying" but if a week later you have ten more extra servers, what does that mean? It's dynamic, not linear...
There could be a lot of reasons for "shortages" of servers. Perhaps people are on vacation or working and can't afford to spend time and money putting up servers like they can at other times of the year. Who knows. But people ARE still playing, and modding, so that's all that really matters to most of us.