I have zooms that cover the ranges of 16-35, 24-70 and 100-400, and primes that cover the ranges from 28-35-50-55-85.
But looking back at my catalog, the images that I am most satisfied with, and especially the ratio of images that I am most happy with, all tend to be at 50mm, or fairly close to 50mm (on my 24-70 I often end up shooting the best images between 45-60mm). So I could probably use a 50mm dedicated and still be able to make most of the images that makes me most happy. Actually, I might just have ended up with a more consistent body of work that I am consistently more happy with. A 28-50-90 kit seems more and more appealing these days, but it is hard to let go of the flexible GM zooms that I have gathered, even though they rarely get used.
But one thing that needs to be clarified in regards to the linked article. The author of that article are talking about using a nifty fifty on a crop sensor camera. So in essence, that entire article is in reality talking about shooting landscapes with a 75mm lens. The author himself clarified this in the comment section of the article after someone raised the question:
"Sorry, yes I'm discussing a 50mm focal length on a crop sensor; the gist being that landscape shots can be captured using something other than a wide-angle lens."