People who oppose fur are also weirdly ok with leather, despite the fact that most leather is gained from India, where to circumvent cattle slaughter laws, cows are deliberately maimed, marched and ferried across the country.
While it's true that a lot of leather comes from India cows, leather is also a by-product of the meat industry, and the hide sold from meat cows is used extensively in cheaper leather products. The treatment of India cows is egregious but the way they are dragged along the country, tobacco leaves put in their eyes to keep them awake and moving, is a more visible parallel to the cows being transported across in trucks so dense that they are standing on top of others who have died in the moving process. It's all cruel, whether it's for hamburgers or for leather. I make no distinctions there.
Relating to fur, specifically, and criticising the more vocal attempts to curb its prevalence as a wasted effort in light of the way our meat, dairy and eggs are obtained, I find to be unhelpful. Ultimately, the less we tolerate the exploitation of animals for their fur, the less we tolerate it in other areas as well. Sometimes it's a tactical decision to wage the "easy battles" because it gets people thinking. If someone says they're anti-fur and buy leather, maybe they will take the opportunity to re-examine their beliefs. We'll never be able to convince everybody, but we can build a consensus.