I think this article helps to better understand this point of view:
http://kaleidic.com/2010/readable-code/
J is a language, like Q and K, also derived from APL [1].
Instead of depending upon layers of abstraction through variable and function naming, this style has a fundamental set of vocabulary (operators) that is insanely expressive in collusion. This allows for concise formulation and expression of algorithms.
However, these languages do not excel in every domain. For example, they're incredible for manipulation of homogeneous data sets, but I haven't heard of an idiomatic way to do heavy socket programming (yet).