Your response is proving my point. Go and read Debian’s philosophy and mission statements. It’s not a desktop-first distro, so why even mention it if your guide is for newcomers who probably want a desktop (that’s what you focus on).
So this is a good tip for technical writing in general, but try writing FOR the topic at hand in comparison to the feature being discussed, and don’t repeat previous comparisons unless a new idea is being introduced. What this means is: don’t mention “X isn’t Y” five times in the span of the topic at hand. It doesn’t convey any new or useful information, and it’s not a constructive structure to your document.
In your case, you don’t need to constantly hammer that “this distro doesn’t do this thing”. It’s not constructive for the reader to grasp what you’re trying to convey.
“This distro has this unique feature” on the other hand is constructive, and conveys useful information to the reader.
Your writing is just trying to move the reader to your point of view.