There are multiple levels of possible generics at play here: the container type and the element type. You can have a map/reduce/filter that operate on any element type (generic elements) while still being specialized to linked lists. On the other hand, you might prefer a generic map that can operate on any container type and any element type, so that you can use the same map method and the same function to map over arrays of numbers, sets of numbers, lists of numbers, trees of numbers, or even functions of numbers!

Haskell allows both sorts of generics. In Haskell parlance they call this higher-kinded polymorphism and the generic version of map they call fmap (as a method of the class Functor).