Well, lets say you are vegan. You want to get certain foods right? Well, by my opinion it isn't a very good idea. Let's say you have to go get certain food and the local grocery store doesn't have all what you want. So, you search everywhere to go get the things you want. That would release a lot of carbon into the air and meat is everywhere! you can buy it at pretty much any grocery store. So, that is my opinion.

While this is your opinion, and I understand that, your argument is flawed in the sense that you say "that if a vegan eats only certain foods and their local grocery store doesn't have that particular item they would go searching all around their community releasing more carbon, rather than just eating meat." This statement does not make sense, as that person will more than likely buy an alternative already present in that store, or buy a different brand, still present in that store.
    A better argument would be that, "Vegan can't be the way to go due to side effects from the lack of essential proteins only found in meat on the person, and the possibility of more pollutants being used to bring larger yields of vegan foods. Being vegan may release less carbon into the environment, it may also have unwanted side effects on yourself." People must understand that they have to take care of themselves and the environment as best they can without compromising one or the other to severely. Whether it's through housing, or consumption of food, and other resources.

I think a lot of the confusion here comes from setting up an unreasonable standard and then when that standard can't be met, invalidate the whole concept.

In this case, Chrissy explains why it might not be a great idea for *some* people in *some* locations to insist on being 100% vegan.

OK, fine.  What about being 95% vegan?  That would still be way more sustainable than eating meat every day.