That's a great solution, actually. Think of it more like a credit card processing fee.
Whether the amount they charge is worth the services they provide is another question entirely.
That it is a percentage of the transaction amount is what I have a problem with. If their business was truly about "credit" they shouldn't need extra charges as they claim back more value from bigger loans/transactions.
Debit cards provide the same service without a percentage charge but without the payment protection. Its a rigged game.