Afterall, gaining rank as a budoka is more than just skill mastery, it's also an issue of maturity.
Maturity is relative and highly subjective. I don't see any reason why one instructor would be a better judge of maturity than one's friends or co-workers.
From my perspective, this thread illustrates how subjective aikido testing and aikido rank is. Different organizations have such differing standards that I personally don't believe rank is transferable among different dojos within the same organization, much less among different organizations.
The other thing that strikes me is how much people aikidoists put their instructors on a pedestal. My boss my have more experience in the profession than I, and more seniority in the company than I, but that doesn't stop me (or anyone else in the company) from challenging his viewpoints in a professional manner. The same thing was true in college. Some of the way "sensei" is ascribed the final, unerring last word is frighteningly cultish (not that I'm suggesting anyone on this thread has that viewpoint).
"The moment you follow somebody you no longer pursue truth"