I don't see these as alternatives, more like complements.

Suppose that making correct predictions does not enable goal-accomplishing actions. We might call this Cassandra's world

It's a memorable name, but it does not need to be called anything so dramatic, given that we live in this world already. For example, most of us make a likely correct prediction that if we procrastinate less then we will be better off, yet we still waste time and regret it later.

Suppose that the path to success is not to update your model of the world, so much as to update your model of your self and goals.

Why this AIXIsm? We are a part of the world, and the most important part of it for many people, so updating your model of self is very Bayesian. Lacking this self-update is what leads to a "Cassandra's world".