Those aren't the vegans that most people are talking about. Being poor and having to eat vegan is different from being vegan because you want to stand out from everyone else with your vegan black bean soy burger with vegan cheese on a vegan sprouted whole wheat bun. If you can afford the overpriced "vegan" versions of typically non-vegan foods, and complain about your struggles being vegan, that's privilege.
When you're poor, you don't advertise the fact that you're eating vegan. You just make rice and beans because it's the absolute cheapest food available. You'll take meat and non-vegan when it's available. But at the very least, you'll survive on rice and beans. It's generally not something that people are proud of.