I have to laugh whenever vegans claim they don't eat living things. Since when are plants and vegetables not living things? They aren't conscious in the same way people are but they do "live," digest, respirate, and reproduce, and some of them have elaborate networks of roots that they use to send chemical signals to each other.
Anyway, not to knock vegans, some of my friends and family are and they seem to be doing great. Just, whenever I'm eating good chicken wings, or ribs, or any meat with a bone in it, I certainly feel glad to have that "carnivorous" side.
And I'm not trying to say vegans are dumb or ignorant about that. Just that I've had the experience of some of them seeming surprised and disagreeing that plants are living things.
You're saying "vegans" as if we're a monolith. I'm sure there are vegans who aren't aware that plants are considered living, but I'm sure there's about the same percentage of meat eaters who aren't either. If every vegan you've ever talked to (or some, since you've made both claims) has this misconception, I'm willing to bet your sample size is extremely small, or you're being intentionally dishonest to support your initial claim.