Very disappointed that the Wallet Card has changed from its original goal of linking all your cards into one... that was the biggest appeal for me. Now that it's just another debit card, I doubt I will use it as my primary method of payment.
Yeah, the fees credit cards charge merchants (in part, to fund reward programs) is why Google has to charge you money to transfer funds into Wallet from other credit cards (otherwise, they'd be losing money when your money goes from a CC into Wallet and out to pay for something.)
Note that there is no fee when the source is not a credit card.