Indoors, where most of the time available light is precious (well, to those who aren't carrying around a strobe), you'll see lots of shallow DOF shots due to the fact that you're trying to get as much light into that frame as you can.
I should also add that, while you gave a very reasonable example, when one considers one thing "unnecessary", others consider it "normal". For example, film is unnecessary in this day and age, when you consider the penetration and presence of all things "digital". I can see the same arguments used by the "digital purists" against the "film Luddites" about sickly chemicals (and silver mining) and high carbon footprints.
Our liking or disliking how an image was made is not enough to make it necessary or unnecessary (or distracting or focusing..."distracting" is such an overused catch-all shorthand adjective in the realm of photography that it no longer means much other than "I don't like it") imvho, of course.