Honestly, while I sympathize with the complaint on a level, it strikes me as a little funny. People seem to play RO with a sense of gluttony. By that I mean they'll play a single map overandoverandoverandoverandover again until they're absolutely filled to the gills and sick of it. Then they'll move on to the next map and run that one into the ground.
I'm not saying that's what posters in this thread have done, but it does strike me as odd that, despite the complaints, the 24/7 servers DO stay populated. I can't fathom why, though. They're often populated with what I consider to be some of the worst/most boring maps. 24/7 Arad? I think I'd rather just not play, thanks.
You want to know what's "killing" the community? The fact that the community itself isn't all that huge. That and the fact that there are a ton of FPS games out there for people to choose from, and more on the way all the time. RO is, like it or not, a niche game. The average FPS player doesn't really dig what RO is about, finds it too slow paced, hates the fact that there's no crosshair, or would rather just stick with their comfort zone in [BF2/FH/BF2142/COD#/etc.].
This results in a relatively small community. It's why, while 50 player servers are a great thing, you don't see all that many of them active. It's why if you fire up the game at 8pm Eastern on a weeknight, you'll see the majority of servers as having only a handful of players on (not including bots, of course), and most players concentrated on a few servers exclusively.
The other reason why people play on the Danzig servers? Because people play on the Danzig servers. Folks go where the bodies are. No one wants to seed a server and sit around for an hour. Not even the admins. So, folks go where they KNOW they can get a good fight immediately. As long as there's at least 10 people who actually enjoy the map/server, others will follow simply because no one wants to "build" a server.
At WolfGaming, we had a hell of a time trying to get our RO servers populated. We ran a Danzig 24/7 server and it was full almost all the time (this was when the map just came out, so no surprise there). At the same time, we had a different server that had a nice rotation, and it lay empty most of the time. People would gladly play on unadminned servers that were FULL of asshats who would TK rampantly (despite server warnings that TKing would be met with punishment....by whom? The non-existent admins?), rather than come to our ACTIVELY adminned server. I even monitored the server using the remote admin from work a few times. It didn't matter.
Why? Because people go where the bodies are. The sad part is that you can have a server that starts getting full for a while and becomes the "default" server for a lot of people. BUT if you have even one or two nights of low activity or technical difficulties, the players will simply move to another server and THAT will become the "default" server.
There are few enough players in RO that the will of "the mob" will dictate where gameplay is to be found. Once "the mob" gets comfortable with a few servers, that's where the action is until, say, a free weekend or a holiday weekend, or major technical difficulties hit and people start looking elsewhere.