You can in Haskell

    min :: Ord a => [a] -> Maybe a
    min = foldl' go Nothing where
      go Nothing a  = Just a
      go a0@(Just m) a 
        | a < m     = Just a
        | otherwise = a0

You can in OCaml

    module Min (M : Comparable.S) : sig
        val min : M.t list -> M.t option
      end = struct
        open M
        let go a0 a = match a0 with
            None    -> Some(a)
          | Some(m) -> if a < m then Some(a) else a0
        let min l = List.fold_left go None l
      end

Point being that these problems with generics are reasonably solved. There are perhaps other problems, of course. OCaml should at least be a suggestion that compilation speed isn't really one of them.