The main problem is that we have around 30-40 people lurking on gamemonitor, the toolbox or on the ingame serverbrowser waiting for a free slot over at hslan. If these guys would risk joining an empty server, then we'd get 2 full servers every evening. I'm pretty sure of that.
I once thought about having a server run with bots that trick people into joining up since it seems that the magic number to make people join a server is above 30 players. Once that number is reached, it will fill up quite fast.
Another solution would be to bring back the 16p or 32p servers like the one F|H used to host. They were fun and filled up quite fast in the evenings with above said people. Plus the excellent 16p/32p maps would be played again.