It seems to me that there is a policy concern that surfaces when one acknowledges the superiority of a paleo-type diet, or any diet that is higher in meat-based protein that the average diet. If it is presumed that a paleo diet is more healthful than others (and I believe this to be the case), there arises an interaction between the policy goals of promoting health and ensuring sustainability.
A 2003 study of the issue found that "The meat-based food system requires more energy, land, and water resources than the lactoovovegetarian diet.
Here is a link to the full text: http://www.ajcn.org/cgi/content/full/78/3/660S
Pretend, for now, that the superiority of paleo-type nutrition in conferring health benefits is universally accepted. We would then be in the position of either endorsing that which is best for the individual and worst (or at least not best) for the group - in this case the world (or a county, continent, region, etc.), or in asking people to accept a diminished potential for health in order that the group see greater benefit.
I should note that the above referenced study finds that both "meat-based" and lacto diets prove unsustainable in the long run, but either way, I think that there are some serious choices of ethics to be made.
Sorry for the long post. I'd love to hear what other people think.