I am happy to admit that the texture of an original print looked at close in a gallery is wonderful, but then again I also appreciate the superbly clean images that others produce. My whole approach to photography is to reduce noise which is essentially what grain is, even if of chemical origin, it is essentially the limit of resolution of a particular technology.
Working this assignment I have taken a series of images from ISO200-6400 on my Fujifilm X100 a good low light camera. I took the photos on a local road in fairly rainy dull conditions, ideal for looking at noise in an image:
Complete image at ISO 200
100% crop at ISO 200
The images have been imported into Lightroom and converted to B&W, but with no other processing. Up to ISO 800 there is little change in the texture of the image, at 1600 and 3200 I still have an image that could be rescued digitally and used up to around A4. At 1600 the noise is very visible, but also not necessarily unpleasant. I have then taken the ISO 200 original and introduced grain into the image using Lightroom:
100% crop of digital grain
The artificially induced grain has a more pleasant look than the very specally ISO 6400 shot and so if I wanted this look I would not shoot at ISO6400 to get the effect. But I do ask why would I want to anyway.