All those committees and instructors doing the accreditation are peers are they not?
Yes, but there's no system or requirement to create a system or checks that a system has indeed been put in place.
Some places have a committee, some don't, in many places it's just up to an individual that never gets questioned.
The Aikikai has no idea how most people are getting promoted - and that leaves things wide open for abuse.
A higher educational institution patterned along the lines of the way that the Aikikai is organized would never receive accreditation from any reputable accrediting organization, and with good reason.
Now, I think that a good argument could be made for a very traditional system of organization where all ranks and licenses come solely from your instructor and their worth is only judged based upon that instructor.
But then...why would we ever want or need to send money anywhere else?