The FSM (Flying Spaghetti Monster) argument is actually an excellent argument for doing what is actually supposed to do: Showing that being unable to completely logically absolutely prove the nonexistence of an unfalsifiable entity, whatever it is, be it a deity or not, is a weakness and not a strength and that theists often have the burden of proof backwards and think that it is actually a strength that they have no evidence for something that at least seems completely empirically and rationally undetectable.
Of course, I'm not denying that the FSM argument may be often misused, misunderstood, etc.
Of course, I'm not denying that the FSM argument may be often misused, misunderstood, etc.