Well, if "Return of the Jedi" would not have a certain duality in it's meaning, I would fully agree with you. Alas, I always deemed it very cool that you could actually interprete the film title in two ways: You could either say the Jedi as an institution/religion have returned, but you could also say that anakin - the jedi - returns.

I simply expected that the same thing would work for "Revenge of the Sith". That you could of course say, the Sith as a fraction take revenge on the Jedi. Yet, I also was waiting for Anakin's personal revenge for something that was done to him that justified a gruesome revenge. That never really happened and thus represents yet another missed opportunity for a great parallel to "Return of the Jedi".