As for photojournalists, many of them that are using 16-35's are still shooting 1D MkIII and MkIV's, the 16-35 works very well in the pack on a 1.3 crop camera, the 14-24 would not be anywhere near as attractive, that is why Nikon still offer a 17-35 f2.8 as well as the 14-24.
Why would I get one? Well yes the zoom is nice but it wouldn't replace my 16-35, however the Canon 14mm, well the two I have shot with, one a loaner via CPS and one from LensRentals, were both crap in the corners. I do some high end real estate work and currently use the 17mm TS-E for most of it, but when I want wider and not stitch then I have found the 15mm fisheye defished is better in the corners than the 14mm L prime, and it gives a wider field of view.
After CPS adjustment, my 14L is very good to excellent