Want to hear something incredibly stupid? I thougt so.

I'm sensitive to chemicals. If I buy the wrong thing, I will break out in a rash or hives within minutes. No joke. A former friend of mine once tried to get into Mary Kay and asked me to be a model while she learned how to host parties. Within minutes, my face started burning. I went and washed it off right away, but my whole face was beat red and the next day it started peeling. :/  I looked like I had a nasty sunburn for weeks and my face hurt.

For that reason, I tend to purchase only products I've used before or vegan products, simply because that minimizes what I come into contact with by extension. I have a ton of allergies/ sensitivities, but never to natural products. I'm good with mineral products and essential oils. Beyond that, it's roulette.

I also prefer things that aren't made with animal products or tested on animals because it makes me feel better about the product.

I don't typically have issues with sunblock, but I've been buying the same brand for decades. If that brand was ever discontinued, I'd pick a more natural product like the one you mentioned. Probably not one with pigments, though, because that just looks silly and tends to collect in odd places. 

Maybe the labeling is odd, but it's written in a way that appeals to its target audience. While "Vegan" doesn't necessarily mean it's chemical-free, it would catch my eye long enough to read the package because it would signify the brand is choosy about what goes into the product. Moreover, people who are into protecting animals would want a vegan product- not because they'd eat it, but because they generally take philosophical issue with animal products in general.