While I sympathize with your sentiment – and share the mindset during my day job – I believe that this type of "what practical applications does this have"-thinking is making us short-sighted and preventing us from being able to move past our current local maxima, to cross the adaptive valley[1].
I'm not expecting the whole engineering field to start exploring the question of what pure mathematics (and not some watered down for-engineers version) can do to fundamentally transform the the way programmers think and talk about what it is they do. But the fact that there are almost zero people from the geometric side of pure mathematics (though again, there are plenty of logicians) working together with everyday programmers, that's what I wish I saw more of every time I see one of these explanations of functional programming that seem almost always to be pedagogically colored by logicians hands.
Cross the valley, sure, but what points to the valley right now? Useful abstractions arise out of concrete issues with present approaches. What are some of the concrete issues in software development which this abstraction could help with?
