Moogle also seems quite lively. I play in the evening on weekdays, which I believe are peak hours on a European server. Not sure what it's like outside peak ours.
But it's true people chat very little in the public channels, except for FC recruiting, FATE parties and dungeon/primal runs. And the occational need materia meld / want to meld materia-shouts.
My suggestion is try to run your own FC, as you are better suited to handpick the people you play with.