The analogy works fine. We have the politically motivated FSF on the "meat is murder" side, and on the other hand the Open Source movements belief that open source is simply a more practical way to develop software on the "healthier lifestyle" side.
I wouldn't expect PETA to stop with their off-putting campaigns ("Your Mommy Kill Animals"), it is what they genuinely believe, and for them keeping silent and advocating "a healthier lifestyle" would be so far from their viewpoint that it would practically be a lie, even if it might win them more friends and influence.
Same with RMS. His views are radical, and toning his messages to make them more palatable down would be dishonest to who he is. Let someone else play the moderate and practical.
Of course, moderate and practical people don't dedicate their life to a message, be it "a healthier lifestyle" or "a better way to develop software". The Open Source spokespeople like Michael Tiemann or Tim O'Reilly) tend to get distracted by having a life to live.
And let's not forget that RMS' views create the space that moderates inhabit. In other words, if there were no RMS, the moderates would be the extremists and we'd all be poorer for it.
The difference though, is that usually the moderates have the pulpit and the radicals are ever marginalized. That hasn't happened to a great degree here. Stallman is still the front man for the movement.
That's strange, all of the vegetarians I know are very clear that being vegetarian adds an extra difficulty in living a healthy lifestyle because getting enough protean is difficult. Vegetarianism, for them, is entirely a moral issue, and is in fact a detriment to a healthy lifestyle.
I know people like that, too. However, if I had to bet money on the primary motivation of the majority of the world's vegetarians, I would bet they hold ethical arguments against eating meat.
