Certainly in the modern age that may work if you are prepared to spend enough time eating.
You only have to look at the OP to see that vegetarian Hominids spend 10 times as much time eating as we do.
I would venture to suggest that those you speak of do not live entirely on such uncooked food as Horse or Deer flesh, also in the northern hemisphere such a diet would require imported food stuffs to supplement the lack of vegetable matter in winter. Also such enthusiasts would have a greater choice than our ancestors
A modern human has the potential to meet their grand children, and even great grand children, a fact that we are almost unique in as a species. My 4 yr old grandson spends much of his time with me and my wife, as we are now 'non-productive' we have time for him. It was probably always so. Also such child minding leaves the parents to forage and hunt, thus there would be an advantage to an older generation.
A modern human would probably lose all their teeth by their forties on the type of uncooked food available in temperate regions...... and how long could they survive without teeth on uncooked food?
I watched a TV trial on this subject some time ago, it had to be curtailed as the subjects simple could not survive on that regime. A doctor and other such were available and it was found with many food stuffs that would have been available that more enegy was expended in digesting the same than was released before being voided. That way leads to starvation.
Modern humans have a narrow rib cage, all other vegatarian hominids have a wide basal structure to make room for the larger gut.
You may wish to read this and similar....http://www.google.co.uk/url?sa=t&source ... 0Q&cad=rja
this is even more telling....http://www.google.co.uk/url?sa=t&source ... iQ&cad=rja
and again....http://www.google.co.uk/url?sa=t&source ... 2Q&cad=rja
First people deny a thing, then they belittle it, then they say it was known all along! Von Humboldt