APL is from an era where impressively functional code that looks like line noise (another obsolete concept) was considered heroic. Other examples of such code are text editing and text formatting macro languages. Recall that EMACS stands for "Editor Macros" because that was its original implementation.
Back then, computers were so limited relative to human capability that this was still a good thing. Those days have gone. The bizarre syntax of APL has had its day. Its powerful array manipulation primitives can easily be brought forward into a language with modern syntax, and haven't they? In my company there is a lot of Matlab usage but I'm personally not knowledgeable.
> Its powerful array manipulation primitives can easily be brought forward into a language with modern syntax, and haven't they?
Kind of. The languages that one might expect to do this (Julia, R, NumPy) have picked out a few things from APL in an inconsistent way, leaving a lot as well. For example most are missing the generalization of prefix sum that APL calls "scan". So in [0], Conor was able to translate some code to every language in the APL family but not yet any outside of it. Another one, I don't think I've ever seen Replicate[1] outside the APL family. It's a generalization of filter to take an arbitrary count instead of 0 or 1 that's often useful if you know about it.
[0] https://github.com/codereport/array-language-comparisons/blo...
replicate(inds, v) = mapreduce(((i, n),) -> fill(v[i], n), vcat, enumerate(inds))