Bah, to me the issue boils down to reality before aesthetics. I do like the feeling that grain gives an image but my reason for that is because its a real thing. Real visuals are filled with chaotic depth that our eyes can get lost in and changes from one instant of time to another. Film that captures images in a grainy way feel more seamless to the way I see in the real world (albeit less fine of course). By comparison, even a fantastic film like Apocalypto feels slightly less real to me with the overly smooth, non-deep visuals it got from using a digital camera.

After that, I find it insulting to think that an old movie has to be smoothed out by some computer program for me to enjoy it. It's absurd to say that grain equals a lack of clarity. I actually think my brain does a far superior job of figuring out what I'm looking at before I need some DNR or "Lowry" program to assist me. When I look at a grainy image I see the separated flecks combining into whole objects and I lose no detail (as apposed to looking at Lowry's "fixed" Sleeping Beauty which looks soft and blurry at parts). In light of that, preserving the statistical reality of the real photons and real molecules that interacted to capture real world images is very important to me. Reality should have value in and of itself when all things are equal. So, then, if grain preserves reality without sacrificing clarity (since brain is already good at piecing it together) why should we then go back and change things for no reason?

Seriously, do the brains of people who greatly dislike film grain function so differently from my own? Are they unable to compute a fleck of light and color as something that should be combined with some other, offset flecks of light and color? I never even noticed film grain until people started talking about it so much. Now that I've been watching for it I'm convinced it feels more natural and real.

(Only after all that will I agree that grain can be an interesting aesthetic choice.)