Claim: leather is ok because the other parts are more in demand

Details

The claim here is that vegans should not be against leather since it's a useless byproduct they are throwing away

Problems With This Argument

1. This is based on a false assumption

Raw animal hides do cost money and are not free], especially if they have been processed. So by buying leather commodities you are supporting the infrastructure that brutalizes animals.

2. The use of the whole animal is irrelevant

It doesn't matter if the whole animal is used in calculating what is done to animals as unethical, any more than it's a defense that one disassembled and parted out the entire car that one stole as a defense of stealing cars. So all of these objections apply.