...-in the creators opinion, for the tasks that it solves for them
Reading the article though, I'd say a good objective argument is made that Fexl is "flawless", insofar as it being the "thinnest possible functional programming layer on top of C." Whether that's useful or good is another matter.
(a (b (c (d (e (f x))))))
(a; b; c; d; e; f x)
Is not required so isn't the thinnest possible layer.Whether it's preferable to a homoiconic s-expr is subjective.