How does the eCS of a diamond indicate its cut quality?

The major Gem labs have been working for years to set a system to qualify Cut quality of diamonds and now after some 10 years and millions of dollars they have systems that indicate to the public that a diamond cut, accoring to them, Excellent or ';O'; which we feel is off the mark. Since the eCS system indicates if a diamond is Cut = 1,000 it is Ideally Cut, the best shape for the best Sparkle, or a variance from it.( less than 1.000)