I've heard that "joke" more times than I've ever heard vegans announce they're vegan.
How do you know someone is insecure about their diet? They'll tell you a joke about vegans.
It's a step in the right direction, but the dairy industry takes a huge toll on the environment all on its own.
I know it does (having grown up around the industry), but I don't think we need to go to such extremes. Lots of things have environmental tolls that don't receive anything like a tenth of this sort of absolutism.