In other words, I guess I have absolutely no problem with conditional assistance (although in this case, veganism is a somewhat ridiculous condition -- I maintain that vegetarianism would be a fine one).

I would say that in this case, the exact terms of the conditional assistance makes a difference. If the population that you're trying to get on board with veganism doesn't understand the shear challenge of maintaining a vegan diet, if the population has essential zero culture centered non-meat, non-dairy, non-fish-oil, non-honey foods, then you're going to see a lot of malnutrion-related sicknesses down the road.

For the less-informed, the deal has the potential to do a lot of harm. Many would call that the condescending liberal attitude, but I'm of the opinion that it's simply not fair to expect people to understand the risks involved without the proper resources and knowledge base. Which PETA is certainly not providing in this scenario.

(There is also the distinction that no one here is arguing that the assistance be made illegal, we're only debating the ethical (moral?) side of it)