I think vegans and even meat eaters should be growing more of your own food. I'm a meat eater but I still make an effort to grow some stuff. Maybe someday I will even have a pet chicken but for now I still struggle with plants. lol I think vegans would have more credibility if they had some amazing home grown organic veggies in their backyard. I think vegans and non vegans should both agree that even the organic options at the supermarket suck.
I had one summer where I had a HUGE garden and when everything started to be ready to harvest, all I had to buy at the grocery store was butter (I was vegetarian then), pasta and wine! It was great!!!