Well... if someone requested I cook them BSE-infected meat when there's perfectly good non-infected meat to have, I think (hope!) most people would offer to coo

Well... if someone requested I cook them BSE-infected meat when there's perfectly good non-infected meat to have, I think (hope!) most people would offer to cook the non-infected meat instead, even if it's not "the kind of food they wanted to eat". Why? Because it's ridiculous to demand BSE-infected meat, at least to someone who knows of the potential health effects. Some people draw that line elsewhere. I could picture someone else saying "it's ridiculous to demand meat, at least to someone who knows of the environmental and financial consequences, when perfectly good food exists that does not have the same consequences." That's putting the line elsewhere, but it's just the same line. It's not about cooking for one's principles, it's about respecting them while offering to cook for someone else.