Lymbery doesn't ask the world to go vegan what he asks is that the farm animals are raised (and eventually slaughtered) with care and compassion.
He also speaks about environmental, economic, ethical and health problems that conventional farming causes.
I wonder why the authors or the publisher didn't add some pictures of modern factory farms and animals. Could it be because often these pictures are distressing to view? Then it's really dumb move as one picture is worth a thousand words.
Here's a link to one of the many videos about the meat industry on YouTube.