red_doghubb wrote:
A militant vegan would on principal boycott places like that. But just about anyone will put aside morals to pee.
One can still get no dairy/no meat options at fast food places. Subway for sure. If you're saying vegans shouldn't want fast food for the very fact fast food place might sell non vegan options, well then you've ruled out every "fast" food chain not to mention almost every restaurant and diner in America. I have a
hard core vegan Indian friend. Even she will eat in places that serve non vegan foods in addition to vegan. She will politely if firmly tell the owner it would be great if the place served more vegan options or even only vegan, but she's realistic. And not even she can turn down a clean bathroom (!) in a restaurant in India.

The fast food industry is not only a major source of revenue for the meat industry, they're mega-corporations which promote the mass production and consumption an objectively unhealthy product. For something like McDonald's, not only can you critique the "food", you can critique their unethical business practices, their miserable labor practices and their harmful environmental impact, among many other things.
Put quite simply, if someone cared enough about animals or the environment to practice veganism (for reasons not health- or religion-influenced), it's hypocritical that they would go on to support companies which contribute to the detriment of those causes. They might as well go out and buy some leather shoes after buying a round of "impossible" burgers.