I really don't understand this. The debate over generics had nothing to do with "computer sciencey correctness" goals, they had to do with ergonomics. Of course, from Ruby, the idea of typing your code is completely foreign, but imagine if a function only allowed one type of parameter, and if you wanted another you had to define it again with a different name.
Basically like allowing flexible parameters makes function definitions more flexible, a lot like all the metaprogramming business in Ruby
