I think you don't really understand what for Founder created aikido. He didn't create aikido so people can reach a shodan in 1 year of very intense practice or in 7 years of medium effort practice. In fact he didn't care at all about ranks and was giving them as candies, to whoever asked him for. Ranks in aikido are used to motivate the will of practice. Particularly to those people who have a weak spirit.

Aikido practice is about to purify and polish your body/spirit, so it can reflect the reality in more and more perfect way and the techniques are the tools used in this process. With perfected mind you take more accurate decisions and actions. When you progress on this path, your life become happier, as well as everybody's life around you. Looking from that perspective, the speed of reaching the ranks is irrelevant.

Of course as you are not practicing aikido, this explanation may look like nonsense for the moment.