Honestly, I am not quite sure what you are asking - or on what topic, exactly, you are looking for insights.
Are you essentially saying that you'd like to see PayPal be a payment option for AdWords?
I will pass that feedback along, if so. Please note, though, that PayPal was not a payment option for AdWords, long before the advent of Google Checkout.
Not having been a part of that decision making process, however, I am not able to speak to why that is the case.
AWA