The purpose is anything you can do with DNS records including TXT records.
If you can't imagine how to use that to authenticate everything else then you should try to think harder.
But to be fair I don't care enough about the usecase of events distributed in the ether so I won't try to prove that signed DNS records are sufficient to satisfy that use case as well, although it is easy to show that that's how all credentials in the universe work, using a reliable PKI.
So you will have to think this through yourself, for me I only care about fixing the usecases that are actually desirable, all of which don't require signed events in the wind, instead they very much depend on reliable hosting.
