I would think the idea is to keep as many people as possible on as members of the forum - if they don't participate, I'm sure there is a very valid reason!!
Perhaps they have indeed found the site isn't what they expected, or have lost interest in poetry, but maybe, just maybe, some of them have just been really busy, and don't get to check on the site.
I myself have been studying for close to two years, and trying to juggle what is considered a full time course, as well as work, and travelling to Perth et al, plus other commitments has made it such that, to come on to the site is just too hard. There is so much stuff to wade through sometimes, that it is easier just to stay away! I do pop in from time to time when I can, but if I hadn't done that, and I was wiped off the register, I certainly wouldn't bother joining again!!
I don't believe the extra names on the members list really make any difference to the speed of things being processed - but maybe Manfred can clarify that. Certainly, if it does, I doubt it would affect do so by much at all. And just maybe, a few of those members will return one day if we leave them be.
Just saying!!
Irene