I very much agree with your point on academics pursuing programming language theory for the sake of theory, and not for language design. I don't want to disparage FP research as a whole, but it seems to be the area of language design that cares the least about practicality and I don't really know why.
Being an undergrad doing my dissertation into programming language design, it seems that FP evolved from an area of research that was very much tied to the theory of computation and never really danced with the practical side of software engineering. Of course there are a few languages that have tried to marry the two (OCaml, Rust to an extent) it seems to very much a mathematicians game. Of course I love the math but it gets annoying to explain that no programmer should have to have a working understanding of category theory to use a language effectively.
Being an undergrad doing my dissertation into programming language design, it seems that FP evolved from an area of research that was very much tied to the theory of computation and never really danced with the practical side of software engineering. Of course there are a few languages that have tried to marry the two (OCaml, Rust to an extent) it seems to very much a mathematicians game. Of course I love the math but it gets annoying to explain that no programmer should have to have a working understanding of category theory to use a language effectively.