For instance, nowadays the Criterion Collection always puts the directors name on their redesigned covers. And in the opening credits, most films say something along the lines of "A <director's name> film".
But in television, it's the writer. For example, everyone knows Only Fools and Horses belongs to John Sullivan, The Fall & Rise of Reginald Perrin was made by David Nobbs, while Seinfeld was made by Jerry Seinfeld & Larry David (among others).
Even if the writer created the story and wrote the script, the main credit of a film still goes to the director. Why are the industries different?