I mean, everyone in the world switching to a vegan diet would be better for our environment, but there are a lot of factors that make it really hard for everyone to do that. Everyone has to be educated on how to cook vegan foods, or even pick vegan meals. Prices for vegan foods might be more expensive or less accessible than foods that involve animal products, as well, depending on what stores are around you, and what they sell. Plus, you have to convince everyone that there's an issue with the environment in the first place, and a lot of people (stubbornly) believe that there isn't one. Also, a lot of people don't seem to believe that a strict vegan diet is healthy, and would refuse to eat vegan (as evidenced in this thread, heh). You can't really force these kinds of changes on people; they'll rebel. People have to want that change for it to work, otherwise we're just acting a bit like fascists...

Change is hard. Life is hard.