"Generics" (a.k.a. parametric polymorphism) might be terrible for code clarity in a verbose language with subtyping and little to no type inference, but in many languages they actually improve code clarity:

map : (A -> B) -> [A] -> [B]

It's quite clear from the above type signature what this function does and does not do. It can only use the supplied A's to create B's using the supplied function. It cannot do anything else with the A's and the B's. To me, that is clarity.