I understand that Veganism is more than just a diet. Its a lifestyle, culture, pledge to a certain set of morals, etc. It can be as important as religion is to a devout religious person.
A person on the Carnivore diet can make the same point. A person that subscribes to a political identity could also make your same point. This slippery slope leads to Nazis being able to call themselves minorities, because technically, Naziism is a culture, too, albeit a terrible one, and they are very thankfully in the minority of political beliefs.
To put the shoe on the other foot, how would it sound to you if someone on the Carnivore diet, or on the Atkins diet called themselves a minority?
It just doesn’t make sense, because dietary choices, are just that, choices. While actual minorities, like POCs and LGBTQ people, are born the way they are. They don’t have any choices in the matter.
Don’t get me wrong, dietary choices can be a super serious matter, and I am not saying that people aren’t discriminated against for them. I just think its wrong to call someone a minority based on any sort of dietary choice, at least in the same context that minority is usually used.
Religion, by itself, is normally not a qualifier when we refer to minorites, as that word normally implies an ethnic or racial minority. However, there are some religions with ethnicities tied to them, e.g. Jewish people, and Muslims, so the line can definitely become a bit blurred.
Jewish people are a minority in most places because of their ethnicity, not their religion. Muslims are often referred to as minorities in most places, because most Muslims are ethnically related, at least as far as the Western world is concerned.
Some also reuse the word minority interchangably to refer to religious minorities, political minorities, etc, which further blurs the line, but the most common use of the word is in reference to race or ethnicity.