To start with, I don’t think privacy is that important.
It makes more sense when we start talking about privacy in concrete forms. It's about not giving any entity more information than it really needs in order to perform the service they claim to provide. For example, imagine how much better credit cards would be if the number was randomly generated, only valid for a single purchase and only the credit card company knew your name and address. Credit card scams would mostly be dead in the water and card readers would be rendered useless.