Veganism on, and in, your body.
Many people wonder why people go to what they consider to be the "extreme" of veganism. After all, vegans are asked, chickens aren't killed for their eggs, sheep aren't killed for their wool and do you really care about snails and silkworms?
The thing to understand about veganism, as a philosophy, is that it starts with the precept that we, as humans, do not have any right to "use" animals for anything. That our use of animals, who have no choice in the matter, is a form of exploitation. And that we should avoid, to the extent it is possible, all forms of that exploitation.
It's helpful to realize that when vegans have that philosophy as a starting point, the extent of the harm to the living creature is simply moot. Vegans do not want to participate in what they consider to be exploitation, just as many other people don't want to buy clothing made with sweat-shop labor.
Further most vegans believe that the vegan lifestyle is healthier for people, healthier for the environment, and of course healthier for animals.
For those who don't believe in this philosophy wholesale, there are still many reasons to avoid all kinds of animal products, and almost every reason comes back to the inherently cruel practice of factory-farming.
Factory-farmed chickens, sheep and dairy cows live in appalling conditions. It's not just the fact that they are packed in tightly and live in their own filth, but each of these animals is subject to routine mutilation without anaesthesia. Battery chickens have their beaks cut off to prevent them from pecking themselves and other chickens as they react to being kept in unnaturally confined spaces. Lambs born for wool production are castrated, have their ears punched through and their tails cut off, all without anaesthesia.
One might think that wool production is benign like getting a haircut, and perhaps it was that way before sheep were bred for constant wool production, rather than seasonal production linked to their natural molting schedule. Now, sheep are sheared before they naturally would shed their winter coats, then the wool grows back during the summer months. Many sheep die of exposure (heat and cold) every year.
Worst of all is a technique called mulesing. Merino sheep produce the most wool because they are bred to have the most folds of skin. Unfortunately all those folds of skin become breeding grounds for fly infestations around their tail area. The factory farm solution for this problem is to carve off folds of skin, yes, their skin hoping to create a smooth, scarred surface where the flies can't lay eggs. And no, they don't use anaesthesia for that either.
There is nothing benign about factory farmed animal conditions, and it's pretty hard to make sure you're not getting such a product.
That brings us to that qualifying phrase I used above: "to the extent possible." I am a long-time vegetarian who believes in the vegan philosophy, but have had a hell of a time adhering to it in my diet. I do my best, which isn't good enough, but is better than doing nothing.
I started out considering vegetarianism 17 years ago because I felt sympathy for the conditions of factory-farmed animals, antipathy for the violence of slaughter. But what sealed the deal for me was thinking it through: there was no reason not to be a vegetarian. I am not physiologically required to eat meat. I am not constrained in any material, important way by my vegetarianism. This goes double for what I wear. Being a vegan in my clothing and accessory choices is a piece of cake.
I'd like to close by turning the "why vegan?" question around. When you know that buying vegan products can eliminate your personal contribution to cruel practices, and when you know you can get both function and style with available vegan alternatives, then I think the pertinent question is really: "why not vegan?"