It's an interesting point.
I own the Sigma 17-50 f/2.8 which - for an inexpensive and fast zoom lens - is remarkably sharp at all focal lengths and apertures (even wide open), with easy-to-correct distortion and vignetting. The worst of its minor foibles is purple fringing at wider angles, especially in the corners - but this is easily remedied. It's a great walk-around lens when you don't want to be switching primes every 15 minutes. That said, the rendering has little character, IMHO. To coin the term used in your example, it's rather "clinical".
I have other zoom and prime lenses that aren't edge-to-edge sharp like the Sigma, and may be considered quite poor performers in several other ways optically, yet the overall way they render lends great appeal... perhaps not for every photographic occasion, but in certain situations.
When all's said and done, a lot of lens reviews are - for the most part - subjective, and based on the individual photographer's preferences