adrasteia1:
Many have players in common, so it may just be that the games fill up quickly once word of them gets around.
I think this is closer to the answer. Being that 1st Ed 7th Sea is, what, 15 years old? It doesn't crop up a lot, so when it does, the people who love that game/line tend to jump on it. I see the same thing happen with some old World of Darkness games, with the same users cropping up every time a game gets in motion.
I've never played 1st Ed, but I did just get the books and would love a chance to play it if someone else thinks of running it. I'm just not holding my breath right now, however.