It isn't completely irredeemable in a different context. Such as if the network supported expedited operations for things. Imagine if Ethereum had a built-in or special smart contract that was a wallet contract. It has an owner that is just some address (another contract or desktop wallet). If Ethereum expedited changing ownership (where ownership changes are signed messages of the current owner so there is no trust involved), then the idea works.

Edit: wait, no, that shouldn't be much faster, if at all. Still need to get it in a block and, IIRC, Ethereum is account based so this is basically how transfers already work, just using arithmetic...