There may be different observations (e.g., experiences that seem to be experiences of a loving deity) that are more likely if theism is true than if the Hypothesis of Indifference is true.
Finally, rather than attacking the argument itself, one might instead argue that, while it is sound, the conclusion is not really a significant one. For what matters is not whether there is some evidence relative to which it is unlikely that theism is true. What matters is whether theism is improbable relative to our total evidence. But, then, suppose that we introduce some different observations—\(O^*\)—such that it seems plausible that \(O^*\) is more likely to be the case if theism is true that if the Hypothesis of Indifference is true. For example, \(O^*\) might be some proposition abo...