A wonderful take on why film is still very useful for motion pictures:
I shot one reel of 16mm film in my life. It was Tri-X I believe. I shot it through an antique 16mm camera I bought on Ebay for $75.
I developed the film myself. I do not recommend doing that.
However, if I was considering making an actual movie, the arguments in favor of film seem outweigh the arguments in favor of digital. That may change over time, but since some of the arguments have nothing to do with image quality or grain, there will always be some advantages for film. For example, Martin Scorsese argues delayed viewing for actors and himself is absolutely necessary for properly reviewing footage and keeping the most important decisions in his hands.
Just like with still photography, however, it seems as though it's a luxury for the few who still care.