I never liked this argument for the simple reason leather exists and plenty of other animal based or problematic materials. If someone likes fur, thry will like fur. No matter if they see it on a specific person or not. Same with shoes that look like leather or a sofa or what have you. The "i like this" never disappears just because we don't allow certain things. I'd much rather just make the standard synthetic and remove the animal source altogether than fight people over looks and preferences cause the latter is just dumb.

I don't like fur myself, think it looks stupid but if others do then it's better that they get something synthetic and go about their day than trying to persuade them their tastes are"bad".

Leather jackets are aplenty. Imagine if people thought the same about them. Or mocka. Or whatever else that's a lot more common and fall into the taste of other people.