for me, i personally hate credit cards. ill never get one if i can get away with it. but honestly, i dont see why netflix cant charge you straight from your PSN wallet (like a package download every month, the same way you pay for playstation plus) if you dont have a credit card.. doesnt seem like an impossible option to me.
I think the problem would be that you're effectively making Sony the debt collection agency or middleman. Netflix is an account seperate from PSN. Why would PSN collect your membership fee and pass it on to Netflix? What's in it for them and who would you contact to dispute a charge? Too much liability.
actually you can use paypal, you just need to pay from your computer not the PS3, just go to the netflix site, and in your account somewhere, you can go to billing info, and there is an option to set up paypal as your billing choice, and paypal can take money directly from your bank account, so no credit card needed.
You still need a credit card to use paypal for netflix( they make it a requirement for recurring charges). I pay through my bank account if funds are low on paypal otherwise. You can work around this requirement though with one of those prepaid credit cards if you have a "verified" Paypal account( as I said Paypal draws funds from my bank if the Paypal balance low but I always try to keep about $40 in it at all times as it covers 4 months of netflix).Paypal's automated system won't accept the prepaid cards in the online form because there is no billing address tied to the card but the support reps can input them manually since they have the same expiry( about 3yrs) as a regular credit card.
actually i had netflix and used my debit card to get it---so YES you can use a debit card.
the reasoning behind there must have a credit card is because the mailed out /dvd/blu rays----a way to collect if you dont send back---they just need to make a digital only version---which they announced earlier this year then scrapped