Absolutely not being sarcastic: one problem it solves is that it is very hard to read as a beginner, so it can be intimidating (although it becomes much easier to read a bit later). This, coupled with the general arrogance of k/q practitioners (again, not really saying this in a negative way) and that k, kdb, etc. deliberately doesn't give you guardrails makes people who write k/q seem a bit 'mythical' and make them feel very clever.
So I think k, q and kdb are fun to work with, but one of the major components of its success is that it allowed a community (in finance) to evolve that can earn 50-150% more than their peer groups who do the same work in Java or C++. 10 years ago a kx course cost $1500 per person per day.
To note that those are typical prices for enterprise level certifications, including some products that some Java or C++ devs might need to interact with, when working on those kind of environments.
So I think k, q and kdb are fun to work with, but one of the major components of its success is that it allowed a community (in finance) to evolve that can earn 50-150% more than their peer groups who do the same work in Java or C++. 10 years ago a kx course cost $1500 per person per day.