There's simply no way for a single number or ranking system, to provide a feel of what it might be like to actually play the course. If you're looking for that, you're just fooling yourself.
Not all of us enjoy the same types of courses and features to the same degree. That's why good reviewers describe the courses attributes, so the reader can decide what to put an emphasis on for themselves.
It might even vary for a visiting players depending on how much time they've got in the area. If I know I'll be tight on time, I might choose to play a less interesting course that has great navigation and flow, over a "better" course with navigational issues.
If I have the time, I'll probably choose the latter. Which one I find to be more enjoyable may depend on criteria that can vary from one visit to another. The current system allows me, as a reviewer, and you as a reader to be more objective than an ordinal system.