[marcusmolchany]

To your first point, someone could implement something like Hexel using a distributed ledger, but it would not have the trustless components of tokens that exist on the blockchain.

The first immediate feature of using a blockchain is that token holders do not need to worry about a private distributed ledger shutting down its service. A future feature we have planned is a developer program where anyone can submit smart contracts that do interesting things with tokens. For this to work with a distributed ledger you would need to implement your own public API for interacting with your ledger.