Well, with Seekers specifically, there are a lot of Tias. Not all of them would stay back home on the farm. With the chaos over Eorzea over the last ten years, going out and adventuring is an excellent way to "open up a new hunting area", so to speak.
And then there's all the Nunhs running around. While I recognize that there are relatively few roleplayers playing adventuring Nunhs, I just handwave them by rationalizing that they've been replaced and simply haven't admitted it.
Keepers, on the other hand? I don't know. I do know that Keepers in the Shroud were probably hit pretty hard by the Calamity, so you're seeing (as Ildur mentions) a bunch of them because they simply had to come out.
And then there's all the Nunhs running around. While I recognize that there are relatively few roleplayers playing adventuring Nunhs, I just handwave them by rationalizing that they've been replaced and simply haven't admitted it.
Keepers, on the other hand? I don't know. I do know that Keepers in the Shroud were probably hit pretty hard by the Calamity, so you're seeing (as Ildur mentions) a bunch of them because they simply had to come out.