I fired up Qtracker just now and it seems like there's about a hundred human players (134, give or take, that's including a few servers that have 1 guy in them atm, but there are five servers with 10-16 humans in them, eight with 4-9, etc).
Now the servers you are trying to join might not be among these if they are outside your region (and thus pings are too high). Or you might be getting on when these people aren't playing (due to different schedules or time zones).
But yes, there are servers out there with human players still, believe it or not. Until a game comes along for the PC that does what JKA does only better, I don't expect this to change. It's a cool Star Wars game where you get to play as Jedi in an FPS environment for free, so that's something that will have staying power, even if the game is going on 10 years old... (but thankfully has been re-released a few times in the last few years to keep it on store shelves for newcomers).
I just reset my own server (IP in signature) so I don't expect it has anything but bots at the moment, but that may change... you're welcome to bring your friends and play there if you're interested in Siege/CTF since that's mostly what I have going.