You're right as far as movie titles go, but the movies are a small part of a larger multimedia franchise. When I'm discussing that franchise in the context of, say, the Trek Literature board, which may entail conversations about books and comics that draw on elements from multiple different shows and movies, then just saying "Star Trek" may not be an adequate way of expressing what aspect of Star Trek you're talking about. Even if it's not the name for any other single work in the franchise, it's still the name for the entire franchise as a collective, and there are a lot of conversations that can involve references to both the franchise as a whole and a specific work within it. So it helps to avoid confusion if each specific work has a distinct title.
And I don't think putting the date in parentheses after the title works very well because then you have to type out the whole thing. If I want to talk about Star Trek: Generations, I just have to write Generations and people know what I mean in the context of a Star Trek discussion. That's the value of individual titles -- it's redundant to have to write out the series title when everyone knows what series you're talking about.
And I don't think putting the date in parentheses after the title works very well because then you have to type out the whole thing. If I want to talk about Star Trek: Generations, I just have to write Generations and people know what I mean in the context of a Star Trek discussion. That's the value of individual titles -- it's redundant to have to write out the series title when everyone knows what series you're talking about.