I agree with the child abuse idea as well. Additionally, we have canine teeth and chewing molars for a reason, whether they be shorter than related species or not. If we had herbivore teeth, or if someone was born with herbivore teeth (think flat grinding molars and front cutters, ie incisors) then I would say they are meant to be vegetarians, and even perhaps vegans. But as stated, we aren't designed for that style of living without serious additions to the diet in the form of vitamins etc.
My sister is a vegan, but that's not saying much because she's also crazy as a loon
. I love her, but her style of living and zero compromise attitude drives me (and the rest of the family) nuts.