Later, I discovered LISP (particularly Clojure), and I learned the elegance of expressions. Finally, I learned Haskell, which opened the door for me in the real world of functional programming. After learning Haskell, I discovered that I can already write an idiomatic F# code.

I was an experienced C# developer when I first tried F# and failed... Because I had the whole CLR libraries in my arsenal, and I used to write C# in F# syntax.

I don't think that only syntax is the barrier. People comming with imperative background mostly try to find familiar concepts that are "missing" in FP. In my opinion, this is the main reason for unacceptance...