I think the issue is that you've just described about 90% of the FCs in the game. What makes you unique and different? Do you offer RP? do you have a forum or a Facebook page for offline communication? Are you progression/raiding based, casual, or somewhere in between? Will people drop everything and help someone with a dungeon?

Back when we were actively recruiting in game, my shout went like this:

"Gotta work in the morning? Kids making a raid schedule impossible? FFXI veteran? Join SWARM - the midcore Rank 8, grown up friendly, LGBTQ friendly FC."

Unfortunately, even with our differentiating factors - the large number of FFXI veterans and the fact that we're almost all in our 30s - we couldn't get anyone off the streets to stay for very long.

In the end, we had more luck recruiting friends and family in real life.