I thought I would add my two cents in for this one. I study a style of martial arts (Sanchin-Ryu) where the founder was ranked in different styles, and when he declared his style in the late 70's he was challenged often. These were not sport matches, but the old fashioned out in the field matches. He "won" every challenge match to show his style effective. The reason I bring that up is that Ueshiba also showed that his style was effective and that is what matters (I'm talking about martial effectiveness only right now, I realize that the spiritual aspect of an art is ultimately more important). But, I have been told by many people who are only interested in rank that my rank isn't recognized by anyone because he created the style.
I really don't care if no one recognizes mine or anyone elses rank. It is what it means to me on the inside and what the art has given to me that means something. Same thing in Aikido, who cares if anyone ever recognizes your rank/style/branch or whatever. Look at what it has given to you and how it has helped and changed you. That is what will be left behind when you are gone.