It sounds silly, and perhaps hypocritical, but I don't really like the idea of leather not being a byproduct of the meat industry. Most leather comes from cows (in India in may cases) where the meat isn't eaten, and the animal is killed for just one thing (as opposed to being killed for meat, and having the leather as a byproduct, etc). But massproduced stuff is often always from cows that aren't used for meat, as it's cheaper. That's all.
I'm not sure where you got this info from, but it's quite wrong.
Most English leather comes from South America nowadays, simply because cattle roam large areas free of barbed wire fences so there's less scarring to the hides. Also, they don't have age/slaughter rules like the UK, and older cattle produce better quality leather.
The hides come in raw to be tanned here, and are a by-product, if you like, of the beef industry. There's very little waste.
Indian leather comes from a variety of sources, but agriculture there works largely on a subsistence level so they're not going to waste carcases either.
I appreciate the fact an animal is killed to provide its hide, but buying leather is actually more 'green' than buying synthetic fabrics, which use oil as a base. It's discouraging waste while at the same time reducing our reliance on fossil fuels :)