For most I would think cost is the main thing. With 16mm film you are paying, say, 100 quid for a small reel of film, then you would have to pay again for a digital transfer.
The 'look' of film can be duplicated by processing of the raw hd footage and for most this is the only affordable option.
Having said that I know what you mean about film. I am considoring having a play with super 8 just cos of the look and for the fun of it.