I argue that the less dynamic range of negative films give scanners a tough time. I'm somewhat convinced that many of these scanners are designed for slide film. If that's true then the limited dynamic range of the negative film hinders the process because it has to be "stretched out" in order to fill the entire digital color range. This would introduce more grain as a result of the errors of the CCD.
I first went to film out of annoyance because while my slides retained graceful highlight tones, my D50 bleached them to hell unless I underexposed 2 stops and carefully watched my screen for EVERY PICTURE I EVER TOOK. Not fun when I want to be shooting. Digital is not the same as film.
I agree. There's nothing quite like holding a shiny large print from a negative.