Unfortunately it has been quite a bit quiet of late, mainly due to the weather becoming warmer and residents of Vana'diel just not playing as much. However on the note of what Satha said, yeah much of the lower end zones don't appear very active as most players on this server are lvl 75 on most of their jobs, but there are still a significant amount of new players coming and going often.
Once you reach lvl 20+ and visit Jeuno and start PTing around there you'll find a great increase in population. Its still going to be quiet though cause its just the nature of this game, where players are just not as openly rude in chat and tend to keep everything in LS and PMs.