PayPal ban accounts for high fraud rates regularly. Paypal is so popular that it is a target for any scammer. Its not surprising if the seller does not offer PayPal. Furthermore, the charges that banks demand for fraud are ridiculous. They don't even accept "non-tangible" goods in terms of refunds and purchase validity. Banks still live in the stone age, and rightly so, because they make a huge bunch of cash from fraud by charging the seller. There is no reason for them to change a highly profitable situation.
Until the whole payment system is dragged into this century, there is little you can do to combat fraud, or avoid the complications are are inherent with it.