You don't just have to learn it (that's the easy part); you actually have to grok it, and that's the hard part.

The piece of code |/0(0|+)\ (all 9 characters of it) efficiently computes the maximum subarray sum[0] of an array using Kadane's algorithm. You'll either have to learn K or trust me on that.

While it is possible to break it down to multiple parts and document each, it is idiomatic to just use it and document the whole line. Or not document it at all, because experienced K people know that already. Why call a function "average" (7 chars) when an implementation (+/x)%#x is only 6? Furthermore, you know from reading it what the average of a zero length list is (NaN). Do you know what a function called "average" would return in this case?

I would say the answer to your question is that K is very different than other programming languages, and requires a different mindset. Somehow, attempts to give it a more mainstream face (e.g. article author's "Kerf" project) do not seem to take off.

[0] https://en.wikipedia.org/wiki/Maximum_subarray_problem

I don't know either party but I'd hazard a guess that they're not really offering 500k for a K developer.

They're more likely offering 500k for someone who has a lot of experience managing financial tick data in a KDB environment.

The catch will be that not everyone who has read the KDB for Dummies book (OK, I made that up) will be able to walk into a stat arb hedge fund and add 500k of value.

Yes, I was wondering the same thing. Some guesses: some people may not be comfortable with the somewhat un-conventional syntax / semantics (e.g. no operator precedence, just right to left or as they call it, left of right :) (I'm fine with it myself), or might think you can only get jobs using kdb+/q/k in big cities like New York / London, and may not want to move there. Possibly low market demand (compared to mainstream languages), although high comp, may be another reason. Also people may think you need finance knowledge too, and may not have it. Those are some guesses, that's all. Interested to hear if anyone else has some ideas on this.

Edit: Just saw beagle3's comment after posting mine. Some interesting points there. Still wonder about the non-tech factors though, as listed in above part of my comment.