It's a matter of perspective -- to someone who has taken a university class on lambda calculus/on logic that had a chapter on lambda calculus (e.g. as part of a M.Sc. in mathematical logic or CS), anything in RWH would probably seem extremely basic and superficial. It doesn't even introduce most of the basic things a first chapter in a book on lambda calculus would probably introduce you to.

My degree was also heavy on FP and LP alongside many other themes.

I think the biggest issue is with those developers that never got a degree or were unfortunate to land in a degree that taught programming languages instead of programming concepts.