The one fellow that I know who holds an honorary shodan rank disgraces his rank every time he performs a technique. He has practiced for a very long time in Aikido but made little technical progress. To my surprise, I have seen him at seminars inquire of unranked students what the technique is that was just demonstrated! He seems in a perpetual state of uncertainty on the mats, his movement is tight and rigid, he is poorly balanced, and easily exhausted. Consequently, there is little honor in his honorary rank, for his ineptitude has made his rank the subject of joking and scorn among his peers.
I believe one demonstrates one's understanding of Aikido through the performance of the physical techniques of the art. As far as I'm concerned, being a veritable font of knowledge about Aikido history and philosophy, or having a wonderfully pleasant personality, or having practiced for a long time, have little to do with deserving a particular rank. If one can perform the techniques of Aikido with a level of proficiency commensurate with a given rank then one deserves that rank. If not, then no rank. No amount of well-informed pontification, or friendly smiles, or training longevity replaces good technical skill.