Maybe

What makes most people hostile to animal rights? Do they disagree with the humane side of our arguments? Not usually. Is it that humans have an unquenchable violent streak or blood lust? Probably not. Is it innate greed? Is it that humans have a cold nature? Perhaps that’s only something that’s arisen lately. Do we lack concern for animals? Maybe. These days we’re probably so punch drunk with competing concerns that we feel nothing strongly enough to make any powerful decisions, and certainly not ones that could tip our emotional balance, like taking on a vegan lifestyle.
We see ourselves as sophisticated humans, but in truth we are probably rather primitive - we probably operate from a ‘flight or fight’ instinct, based on a combination of believing animal foods to be necessary along with a primal need to maintain our dominant position over animals. Equally primal is a need to maintain a smooth supply of animal foods (in our shops).
Perhaps this self preservation instinct is reinforced every day at mealtimes, and by it reinforcing our social normality too. Maybe to balance the guilt we feel about animals being killed and enslaved on our behalf we justify it by insisting that we should be free. Free to choose what we eat. And over our adult years familiar foods assure a certain level of satisfaction without which we fear we’d become unsettled.
If we can be convinced that animal foods are ‘natural’ then farming (and killing) practices will not be noticed. And likewise, if we fail to notice those deteriorations in our own bodies, brought about by the continual use of animal products, we won’t see how our eating habits conspire against our instinct for good nutrition. Instead of maturing our taste for healthy foods we continue to enjoy our ‘nursery teas’ and rich dinners and snacky treats. Eventually, usually too late, we realise that something we value in ourselves has been spoiled - the vitality and sharpness we once had is on the wane.
We get used to even that. Perhaps we call it ‘the ageing process’. And then, out of this, come other disasters - we lose confidence in ourselves physically, we’re ashamed of ourselves spiritually, we lose sight of the honourable part of ourselves. So, because of our attachment to animal food we allow our hearts to harden. However much we try explaining it away, we always come back to food addictions and our attachment to thousands of familiar eatables which we’ve grown accustomed to over our lifetime. Maybe we’re slaves of human habit just as the animals are slaves of human beings.