I like this post because I’m fond of using the “what’s the better alternative?” argument in instrumental matters, so it’s good to have an explicit flag of where it fails in epistemic matters. Technically the argument still holds, but the “better alternative” can be a high entropy theory, which often doesn’t rise to saliency as a theory at all.
It’s also a questionable heuristic in instrumental matters, as often it is possible to meaningly critique a policy without yet having a better alternative. But one must be careful to distinguish between these “speculative” critiques (which can note important downsides but don’t strongly a policy should be changed, due to a lack of alternatives) vs true evaluations (which claim that changes need to be made, and therefore should be required to evaluate alternatives).
I believe The Real Rules Have No Exceptions is an instrumental analogue.