You literally asked me the question and are now chastising me for my answer. This is the "how do you know someone is vegan" joke. I pointed out self-preservation to point out that vegans don't go around attacking poor people and don't expect people to keep their principles in those situations. I made a choice I don't expect other people to make. I point my criticisms at the people I know in real life who shop at the exact same stores I do and make similar amounts of money, but still use poor people as an excuse not to change their own behavior.