[littlecosmic]

Corn, wheat, rye, oats, beans and soy are staple foods for humans and are what is often fed to the animals we intensively farm. For the non human-edible crops like alfalfa, canola, etc there is some wriggle room to change to other crops. My main point is that it is a realistic change not an environmental and moral disaster as it was framed.

As far as supplementing B12, I say better safe than sorry, but even that is not straight forward when you look into it.