Couldn't agree with you more, Original, about humans being a planetary pest. I, however, am not about to subject myself to starvation, hypothermia, dehydration and infections out of guilt. She who wishes not to be part of a food chain must consume nothing. In consuming nothing, she'll be a useless hangnail on the universal recycling system, until she dies (very soon) and becomes useful fertiliser.
People don't think. If you cultivate all your own vegan foodstuffs - and you'll have a pretty shit diet, at this latitude - how will you ward off predators, like birds and insects? When you've exhausted your soil, how will you replace the nutrition needed by your plants? How will you process and prepare your food, killing nothing and leaving the planet untouched?
It just doesn't work. We are animals. Get over it. If people want to eat a vegan diet, good luck to them, but I find it pretty hard to buy into the often-associated moral superiority.
I have said that, now I'm poor, I'm morally horrible. I do think it's better to consume as ethically as possible. As things stand, though, I'm grateful for low-priced meats because I care more about my welfare than that of the chicken I cooked this evening.