Why do I need to provide Apple with a credit card to change locations in the app store to download a FREE (yes, FREE) app?
Is all this part of Apple's collective desire to **** off the consumer and drive them off? If so then its working for me.
It's a way of proving that you are able to purchase content from that country's store i.e. that you have a valid billing address in it
From Why can’t I select None when I edit my Apple ID payment information? - Apple Support :
If you changed your country or region
When you change the country or region of an existing Apple ID, you must provide a payment method and update your billing options. If you want to remove your payment method after you change the country or region, you can change your payment information to None.