In Germany there was a court ruling years ago which basically said - a company has no right to tell customers which payment method to use to settle the outstanding debt between two individuals. Especially can a company not force customers to exclusively use a payment method operated by the same company (antitrust stuff).
Because you are NOT buying from ebay, you are buying from another person!
So, the result is that 90% of US ebay auctions are Painpal only while in Germany and some other countries you can use whatever you want
Post your auction on ebay.de and you should be fine (trouble is, most Americans don't search for international offers, they think USA is center of the world)
Cheers
Leo
You are right on the money with your logic. And so is Germany!