I don’t know who else cares about noise, but I do. Actually, I suspect a lot of people do. Would you rather look at a photo in a newspaper or in a glossy magazine or book? I’m betting the magazine or book. Why? Less grain, more detail, richer colour.
I don’t know about 25 years ago, I know 40 years ago we talked about grain, and used ASA 25 slide film because it was far less grainy than ASA 400. And it was much less grainy than if we had to push film. Somewhere along the way ASA 64 came out and it was a bit of a compromise. But in the 1970’s we definitely talked about grain. Now since it is electronic, it’s noise. I upgraded from tiny bridge cameras to dSLR’s because of noise, and upgraded my wife’s G11 to a G16 because I wanted to reduce noise. I would love to get her into a camera with even less noise as she shoots in a lot of dark places without flash, but form factor and ease of use also play into the equation for her. Isn’t noise one of the reasons we like fast glass? You can open the aperture instead of increasing ISO, and you get a sometimes pleasing shallow DOF at the same time. The reality is that even a cell phone camera can take a pretty good, noise free shot in good light, but as the light degrades so does the image. With better cameras, you get a lot less noise in bad light, and to bring in the car analogy in a different way, I drive a van that gets relatively bad gas mileage, but I only have one parking spot and sometimes I need a van to carry more people or more stuff, but that means I’m driving a van when I’m just driving by myself somewhere too. With a 50D and 1Dx, you have the advantage of being able to select the tool for the job. Perhaps the D3/D4 owner only has one body.
By the way, Scott Kelby was given some loaner gear by Canon, and he decided it was good enough keep and switched to Canon.
Who prints? Well again, I do. I hardly ever print for myself. I like slides, so images on a monitor work really well for me. I print for others though, sometimes to go on a wall and sometimes to go into binders. My wife likes prints, so I print on 8.5 by 11 photo paper and she inserts the pages into plastic sleeves in 2 or 3 inch binders. Some pages are one image to a page but others are 4 or 6 to a page. To my amazement, she has 22 binders of them so far! If asked, I would say I don’t print much, but obviously I do. I’ve also done a dozen photo books, a few were printed by Blacks, then I discovered others had better layout software so, more recent ones were done by Blurb and Photobook Canada. Grain/noise starts to be a problem if you are printing a full bleed two page spread (sometimes called “double truck”) in a larger album size. A favourite size is 8.5 by 11 landscape, so a double page is 22 inches wide. In the professional series, books go up to 12 by 17.5 landscape so a double page is 39 inches. One of those starts at $330, but they make a nice coffee table book.