[lokedhs]

I'd argue it's partly because of tradition. If you look at early APL code, including Iverson's earliest papers, it's written with pretty much zero spaces (well, except for where spaces are required).

A lot of APL programmers continue this tradition, and it works for them. Not everybody does it though. I'm one of those people that adds spaces and newlines to try to make the code more clear for myself.

As an example of the kind of code I tend to write, here's the code for the Kap output formatter:

https://codeberg.org/loke/array/src/branch/master/array/stan...

Of course, if you don't know what the symbols mean, a lot of it is probably still impenetrable, but I think this code is less dense than your typical APL code.