I don't think that fraud preventing thing is a problem...YPN pays by PayPal as I know... I think that the problem is that PayPal belongs to eBay, so Google would rather payout by Google Checkout then PayPal
Is not a good idea to give money to competitors. And it is easier for people like me, to get my money directly into my bank account, not in paypal, and then moving it to my bank. I have no problem with current methods.