I voted for adding film grain being a greater sin, but now I'm questioning my choice.
Is film or digital nearer to the Platonic Ideal of photography? Or, which is purer is essence?
If film is the ideal, then transferring the ideal into the imperfect is a greater sin than making the imperfect more like the ideal.
I think I was led astray by thinking about process: at the least scanning uses film for image capture. But it then degrades and diminishes it, where adding grain moves the sinful digital file one step closer to perfection.
Do I need to add that this is all completely tongue in cheek? 😛
PS - What about making an archival print on traditional paper from your grain-enhanced digital file? Does that then completely redeem the digital image?