Personally saw no real problem with the Ancients' arrangement on a more pragmatic level... given they are immortal and don't die of age or disease, only through violence. Considering they also had children and likely saw that as quite important, leaving meaningful roles to those children by your departure (knowing you will reincarnate anyway) doesn't seem like a bad idea. A bit like a forest, where having all the old trees smothers out all the light for all the saplings below unless they are cleared through some other means.

Otherwise, with no one really dying, Etheirys would eventually become quite overpopulated... then, I suppose, they'd be forced to look into space travel.

As an aside, soon this thread will be 300 pages. And it will be beautiful. (笑)