Your examples would have more similarity with suggesting a vegetarian diet as an alternative to a mix or most meat diet. That would be a functional alternative, like suggesting a different OS or Browser.
Veganism more like a political statement that if you eat meat your are a bad person for harming animals. All vegans may be vegetarians but not all vegetarians are vegan.
I will admit there are many OS and Browser purists that might be more like vegans telling you, you are bad for choosing the one you currently use. There are FOSS purists that only tell you to use FOSS because it is NOT commercial not because the software is better for what you need.
Well there are almost religious Richard Stallman GNU/Linux followers.