Nothing is wrong with them. A lot of people aren't used the level of abstraction that Haskell uses, so they look at a specific instance of the structure (often

Nothing is wrong with them. A lot of people aren't used the level of abstraction that Haskell uses, so they look at a specific instance of the structure (often the List type) and think of a name that fits that instance ignoring the more general class. You end up with names like Appendable ( Monoid ) or FlatMappable ( Monad ) both of which give horrible intuition for the general case. I think the abstract algebra names are great because they describe the general case precisely without any preconceptions carried along with them.