[PeCaN]

Regarding 2 & 3, I assume you don't know Q or any other array language. If you do, it's not really any less readable than any other language. Finding bugs isn't particularly hard due to how friendly the languages are to REPL development and how easy it is to trace array transformations.

I do agree with 1 & 4 though—Q (and to a lesser extent, K, APL, and J) are niche languages. However, they're really, really good at their niche.

[haddr]

It has nothing to do with array language, R is vectorized and is slightly more legible than, say clojure, that is not array lang. It has to do with very high density, though.