Is something else better (if so what)?
Otherwise, I don't see anything you can do in an array language that you couldn't do in any other language, albeit less verbosely. But I believe in this case a certain amount of verbosity is a feature if you want people to be able to read and understand the code. Array languages and their symbol salad programs are like the modern day equivalent of medieval alchemists writing all their lab notes in a bespoke substitution cipher. Not unbreakable (like modern cryptography) but a significant enough barrier to dissuade all but the most determined investigators.
As an aside, I think the main reason these languages took off among quants is that investing as an industry tends toward the exultation of extremely talented geniuses. Perhaps unintelligible "secret sauce" code has an added benefit of making industrial espionage more challenging (and of course if a rival firm steals all your code they can arbitrage all of your trades into oblivion).
A few years ago I wrote a pipeline in J and then re-implemented it R. The J code was exactingly crafted and the R code was naive, but the R code was still faster, easier to read and maintain and, frankly, easier to write. J gives a certain perverse frisson, but beyond that I don't really see the use case.
