A 'wallet' is entirely inaccurate and leads to confusion and money loss. Why is a wallet metaphor which I carry in my right pocket easier to understand than a keyring which I carry in my left pocket? The fact that a keyring more closely resembles the model means that it is the superior metaphor.
The reason for using existing terminology for new concepts or paradigms is to ease the transition for the masses who are not on the bleeding edge, nor do they care to be.
Both wallet and keyring are already in the common English lexicon. A keyring is also commonly used within the digital lexicon while wallet is not. A keyring is exactly the correct terminology as a real world metaphor and an established digital term.