If herbivore really meant grass eater there wouldnt be much dispute In reality herbivore is commonly used as meaning exclusive plant eater the choice being between being a carnivore an omnivore and a herbivore The terms are not to be taken as their etymologies would literally imply Otherwise omnivore would mean who eats everything no one eats everything Including nails rocks human babies computers cardboard and grass Now concerning the ancestors of presentday humans that they were in fact omnivores  that they did in fact eat both animals and plants is certainly of interest but doesnt make presentday humans omnivores Many presentday humans are omnivores others are herbivores in the sense that they only eat plants Youre right that the statement that humans teeth and digestive tracts are more similar to herbivores than to carnivores and most omnivores doesnt imply that humans are herbivores but it is often used as if it did and it seems to be in that sense that it is used in the paragraph Now as I said disputes about whether we are or not herbivores or whatever are in my mind completely irrelevant and I am not defending that paragraph Its just that since that paragraph seems to be a discussion on that issue a sentence that implicitly presupposes the issue as settled is out of place