Well SC's proprietary compiler is probably different, but GHC is self-hosted (the runtime system is C but the compiler is implemented in Haskell) and the map and fold functions in Prelude are recursive. Here's the source code for `map` in Prelude:
map :: (a -> b) -> [a] -> [b]
map f [] = []
map f (x:xs) = f x : map f xs
But it is definitely still true that explicit recursion is discouraged as being too 'low-level' for most Haskell code and it's preferable to use higher-order functions instead.
