As a k programmer myself I'd say to take that statement with a grain of salt and at least give the language a chance if you have some spare time. It's certainly true that the community is small and it's certainly true that there are plenty of really sharp programmers in the community but that doesn't mean that you need to be a genius to write k code.
> Arthur Whitney's k and its derivatives have served a small number of highly skilled programmers
Doesn't exactly start off with an inclusive tone.