I think that this is a matter of practice. I write k/q almost daily, and don't struggle to read other people's code, or my own.

Most code isn't clever oneliners, and is quite readable.

Agree with this. The problem is that there's no widely adopted style guide with k or q. A lot of code you find on the web is written in a minified fashion. At least put a new line and indent whenever you can.

K is interesting in that unlike something like Java the hard part is not remembering the standard library. You start to learn idioms for how to do certain things as you use it more. Then you pattern match different parts of the code and it can be very readable.

The fact that every function/operator has multiple meanings, often very different, depending on the actual data passed to it doesn't help readability. It tries too hard to use only symbols, which are limited on an normal keyboard, and so it crams multiple functionalities into the same symbol.