There isn't a fair way of doing it that anybody would universally accept. It's good enough. Frankly, some of the contributions are so far out of kilter, it's a pretty good indicator of where more can be done. How do you compare capabilities? You could do that, but you would never find an agreed standard. That's one reason they've adopted this one, because it's so hard.
On February 8th, 2018. See this statement in context.