One reason we should scrupulously stick to conventions is that in the event that we someday have a long discussion and decide that our old convention is undesirable, our sticking to the convention makes it a lot easier to change.
That is, it would be pretty simple to write a script to move all pages from "Blah blah blah (movie)" to "Blah blah blah (film)", but a lot of work to fix "Blah blah blah (the movie)" and "Blah blah blah, a movie" and "The movie: Blah blah blah" and so on.