When reading both of these books, I at times felt numbed by the large number of statistics, detailing the harmfulness of animal products in the diet, the destruction of the environment caused by factory farming, and the potential dangers of genetically-modified foods. In some ways this was preaching to the choir for me, as I'd been vegetarian and already trying to go vegan for years.
But beyond all of the statistics and doom-and-gloom predictions, there was a stronger message: of compassion. Robbins is one of the very, very few authors who has moved me to tears. I'm hardly a person who never cries, but when I do it's usually because of some petty personal reason (relationship troubles, etc.). But reading his books has showed me not only how wonderful and precious our animal friends are, but how opening up and truly listening to people you may not agree with can be transforming.
I hope more people read his books. I would buy copies of The Food Revolution for my family and friends myself if I thought they would really read it, but I don't want to be preachy. Robbins really does cover pretty much all of the reasons why I am a mostly-vegan vegetarian: health, ethical, and environmental, and has plenty of footnote references for validation and further information. Yet despite what he's written, Robbins himself doesn't say that everyone should become a vegan; he states "I don't care whether you call yourself a vegan, a vegetarian, or an asparagus". He just wants to inform people of the issues involved, and hopes that if enough people are convinced, the world (America in particular) will move toward a more plant-centered diet.