Quantifying the value placed upon the belt is the problem. Qualifying the value based on technique alone is inadequate as well as qualifying the value on a student's character alone. But this is more specifically related to rank in general, whether there is a colored belt involved or not.
Nice. But what I was trying to say, poorly perhaps, was that in BJJ blets have "real value" because people see them as having real value. A white belt looks at a blue belt somewhat in awe, and rightly so. This is a belt that has value.
A white belt might well know all the techniques a blue belt knows, but they don't have the same attitude, the same ability to execute techinque. I have seen people stay white belts in BJJ for 4 - 5 years before getting a blue belt (in our style you'd be lucky to get one in under 3 years) because it took them that long to "get it."
So in Aikido when a person is awarded a 5th, or 4th Kyu, or some belt colour, if the club has such, do the others see that belt, or Kyu as having real value.
In a lot of places this is not the case - the McDojo effect.