only time i use a digital camera (I don't own one, but might borrow my mother's or friend's):
when I'm taking pictures of a film camera.
I only have one film camera . . well, three really, but two of them are currently on ice.
SO for the same reason that mirrors and back scratchers exist, so exists the digital camera. For the same reason that the backs of our heads look foreign to us, we have digital cameras.
Only we have far less reverence for the digicam than we do for the good old back scratcher. The one with all the milage of honest service. Or that nice magnified mirror. How else would we ever examine our post nasal drip?