It wasn’t really that we wanted to have a CRDT per se, but as it was implemented on top of an op-based append-only log CRDT, it turned out to hold those properties, which makes it a CRDT. We wanted to have the edits to be able to arrive in any order or after delays due to network partitions (this was for a p2p network).
My non-techie brother has been staking his 1 ETH he bought couple of years ago and has earned today, in his words, “slightly more than from my insurance savings account in the past 10 years”. I think that’s a really nice use case.
One way to do authorization is to sign each operation/message and then verify the signature to match a public key in an access control list. This also enables CRDTs to work in a peer to peer context.
But as aboodman says in a sibling comment, if there’s a server as an authority, it can simply reject messages from unauthorized clients.