What's the point of a an identity provider if it doesn't authenticate the user? Yes, maybe it's valid according to the spec, but that's not what it's designed for. No need to confuse people on theoretical data differences that don't appear in practice.
What's the point of an OAuth provider if it doesn't authenticate the user? I don't mean to be snarky, but this is something that's widely confused on the internet and by making a parallel statement I think this is most clearly indicated.
The fact is that authentication is required for both. My point is that "authentication" isn't a particular of OpenID 2, and focusing on that when explaining it is what's confusing.
For my part I was very confused when researching the two until I learned to mentally flag answers/posts that focused on this as noise.
