You would have sentences like "a reflex agent reacts without thinking" and then an example of that might be "a human who puts their hand on a stove yanks it away without thinking about it" and this is rational because the decision problem doesn't call for correct cognition - it calls for minimization of response time such that the hand isn't burned.We have to be specific about what we're discussing. The human reflex to pull away from a hot stove serves the human, the human gets a benefit from the reflex in the context of a world that has hot stoves but doesn't have, say, traps intended to harm people when they manifest the hot-stove reaction.
Some broad optimization algorithm, if it trained or designed actors, might add a heat reflex to the actors, in the hot-stove-world-context and these actors might also benefit from this. The action of the optimization algorithm would qualify as rational. A person who trained their reflexes could similarly be considered rational. However, the reflex itself is not "rational" or "good" but simply a method or tool.
Which is to say you seem to be implicitly stuck on a fallacious argument "since reflexes are 'good', any reflex reaction is 'good' and 'rational'". And that is certainly not the case. Especially, the modern world we both live in often presents people with communication intended to leverage their reflexes to benefit of the communicator and often against the interests of those targeted. Much of it is advertising and some of it is "social engineering". The social engineering example is something like a message from a Facebook friend saying "is this you? with a link", where if you click the link, it will hack your browser and use it to send more such links as well as other harmful-to-you actions.
It seems like your arguments suffer from failing to make "fine" distinctions between categories like "good", "rational", and "useful-in-a-situation". They are valid things but aren't the same. Analogies can be useful but they aren't automatically rational or good. You begin with me saying "this isn't inherently good or rational though it can be useful-in-a-situation and you think I'm saying analogies aren't good, are bad, which I'm not saying either".