Apple Store - Credit card info deleted on Apple's end

So I want to access apple store, but I don't want to give my credit card information. Apple says that if you have an Apple ID you have to enter it then delete it after signing in (Create an iTunes Store, App Store, or iBooks Store account without a credit card or other payment method - Apple Suppor…). Why can't you just give us the option not to enter it?

If I go through this process of entering it then deleting it, is the information still kept on Apple's end?

Thanks.