ITT: Seriously discuss the truth in this picture.
Zyklon Ben strikes again.
Anime isn't the reason for the herbivores. It's feminism and general leftist (cue cultural marxists) influence in the world. Men are generally ridiculed or persecuted for traditional male behaviour ("macho, haha, he's so insecure", "what an asshole" etc.), and in Japan, people give a great deal about how they are perceived in society. The young men grow up thinking it is expected of them to be vegetarians, so to speak. Even literally: Here in Germany, there are frequent articles in the news, even in TV news, how men are eating too much meat and how it's bad for the environment (due to the effects of cattle and whatnot), and how women are much "better eaters" and are responsible etc. Most men here shrug it off, but I can see our Jap friends being afraid of what is now considered shamefur dispray.
Then again, afaik, Japan only leads the Western world by a small margin. All Western civilizations decline, women aren't getting children anymore. Of course it's the men's fault. As expected from a feminist society.