The primary point of haskell is making it easier to reason about your code.
>I find reason to question the simplicity of something which is widely acknowledged to take a lot of time to learn, to be mind-bending, and which seems to be impossible to explain simply
It takes a long time to learn any programming language. You create an invalid comparison when you compare learning language X++ after already learning X to learning language Y++ without having learned language Y. Haskell only takes longer to learn if you compare it to learning a language that is virtually identical semantically to a language you already know. And I don't know why you think it is impossible to explain haskell simply, there's a reason everyone points to learnyouahaskell.com when people ask how to learn haskell.
>The virtues of survivors like C and LISP are not all "social issues".
How is lisp a "survivor" exactly? Haskell is more widely used than any lisp is.