I'm not sure what you mean here.

If the card only had your wallet's bitcoin address, and not the private keys, what good would it be? Bitcoin is a "push" system, you wouldn't be able to use such a card at checkout.

If the card had a number on it that linked to your wallet account at some "bitcoin bank," then it might see some degree of success, but I'd be skeptical as to how long it would last, for a variety of reasons.