I described the bioshpere as a bush, and each individual population in it as a twig on the greater bush. DQ himself has said on a number of occaisions that he is still a Taker and doesn't forsee any way he could be anything else during his lifetime. We can adapt and evolve our culture into something non-destructive, but we can't spontaneously transmogrify, not even to another extant form of human culture. I know this is going out on a limb a bit, but let me see if I can explain what I mean. Each variety of life is it's own evolutionary branch.
Takers are no exception.
When something threatens the survival of a particular species or culture, the members therein cannot simply opt to become a different branch, abandoning their own evolution to live like another group on a different branch that doesn't face the same difficulties. Nor can they backtrack to living like they themselves used to live long ago, before their current branch sprouted. I somethimes get a little flicker of recognition. Otherwise you're screwed. This doesn't mean we're especially unfortunate, this means we're just like every other life form.