I'm not sure the rationale they give is entirely valid:
"The Dutch scientist's aim was to show the world that in the future meat will not necessarily have to come from the environmentally and economically costly rearing and slaughtering of millions of animals."Current meat production is at its maximum - we need to come up with an alternative," he said."
My understanding has been that cattle are ruminants and can digest cellulose while humans, being frugivores, cannot (though needed to stay, um, regular. Fiber in the diet and all that.) Since there are millions of acres of land that are too marginal to raise vegetation that humans can easily digest, but naturally grows cellulose-bearing plants, they should be most economically used for cattle grazing. It would actually be much more costly to grow fruits and vegetation digestible by humans on those marginal lands.
And I've also read that the human digestive tract is optimized for fruits, not meat. That we evolved as herbivores and that omnivorous tendencies are fairly recent (mere thousands of years versus millions as frugivores.) Our digestive system is allegedly evolved to handle "fruits, roots, and other succulent parts of vegetables."
