Go doesn't lend itself to functional programming, in part because of its lack of type parametrization. In a language like Scala or Haskell, using functions like map, fold, and filter is clean an idiomatic. In Go, it is so ugly and convoluted that you immediately reject this approach and use for loops instead.
Standing firmly in one paradigm is a good thing for a language IMHO. I've worked in multi-paradigm languages and they suffer from the fact that their communities can't find a common style. "Should I use a fold or a loop or a tail recursion?", or some library designers want to be as typeful as possible, others don't, etc.
