Yamada Sensei expresses it splendidly. I think aikido would benefit if the grades were erased - but how to do that? The way it is, we can only do the next best thing: make sure that students progress in grades as their aikido improves, while we constantly remind ourselves that grades are not the goals of keiko.
A paradox, I know, but hey - so is life.
I guess my question here is - why is that the only thing that we can do? There really is no requirement to use grades, and no way that they can be forced upon anybody, all that it requires is for people to decide that they no longer want to go along with a system with so many negatives and so few positives.
It could happen - and I think it will happen at some point.