Why Does Buy Together Default to $1 discount?

When you add products for Buy Together it defaults to a $1 discount? What’s the purpose? The website has no idea what the discount would be so why would it “guess” the discount is $1. It should be $0, especially in cases where we are using the Buy Together more as a ‘Related Products’ function - which we are. Very odd. Why isn’t it $2 or $10? I don’t see the logical purpose in a $1 default. How can we remove it so it is $0 default.