I like terse code and my style is closer to the early UNIX/K&R, yet I've noticed a lot of people already find that too terse; the "normal" style these days seems to be gradually getting more and more verbose (look at typical C# or Java, for example.)
IMHO the readability argument in favour of verboseness is a bit of a misnomer --- you can easily "understand" a file full of extremely verbosely named functions all consisting of a single line, but that doesn't help at all with seeing the big picture. Judging by the amount of file-flipping and stack-jumping when I have to debug a project in that style, it probably hinders it.
On the other hand, this is "code with a learning curve". You can't glance at it and understand immediately, but once you do take the time to read it carefully, you can understand more of the whole than if it was written in a more verbose style.
There's also a lot of code that's so tightly coupled to some business domain that it's natural to write it in the language of the business. That way you don't have to maintain separate mental models and translate between them.
Talking for myself, I would love a FOSS version of k, but I am sure as hell I would patch a couple of things, and I am sure I would write much worse code than Whitney's (in his style or in my style).
There's a lot of material on their website, though it's not well organized and some of it is out of date.
https://code.jsoftware.com/wiki/Main_Page
I find it rewarding to screw around with, though the only jobs you're gonna get are K/Kx related.