Well some people grow tired of the game and the community. A lot of them, I suspect, quit the whole thing due to them not making new friends in the community when their old friends become inactive.
I would have gone inactive a long time ago, but I've befriended some of the new, (and imo alright), people that join the community, especially they who become IRC regulars. You just don't have to look down upon every newb because the chance is that with the right treatment, a lot of them will contribute loads to the community in the future.