It happens a lot. I know some people in some of the servers I played claimed they quit doing sage becuase of this kind of thing. In one server I played someone even commented in world chat we had enough players logged, but sage could not be started becuase people just wouldn't sign for it.

I understand this kind of thing is annoying when it happens to you, frankly I wouldn't advice people to stop signing for sage especially if they are in a server in which activity is dwindling down. But you could still sign for sage and either play it all afk or just do 2 fights and quit as soon someone camps you. Or I guess as many do, not do sage at all.