Why does iPhone ask for payment info for free apps?

Why does iPhone ask for payment info for free apps?

When you first use your apple store to download apps, it still asks you for the payment info just in case you want to download something that is not free. But don't worry enter your card info and it will only charge your card if you download something that is not free.

Its just the way it works. Its a safe assumption that you wouldn't only buy free apps.

http://support.apple.com/.../kb/HT2534

That's not right I only download free apps it should only ask that if it's not free not putting my info on internet to anyone myself y'all do what you but I guess it's goodbye free apps for me but I have got what I need