Jørgen Jakob Friis
It's interesting to note that this discussion is almost entirely driven by american aikido people who - for some reason - seem to have a quarrel with Aikikai one way or the other.
Consider this: what if a European country turned out to have more practitioners of something very american... say baseball, cheer leading or line dancing, and we started arguing that the national center for this activity should be moved to say Paris... "wait a minute now." I bet you would say. "this is an american tradition, so before we do something that drastic we need to make sure that you are fit to take care of it. First start at national federation, and we'll send some of our best people to check out how you are doing.". Is this entirely unlikely?
Next you would offer us a chance to become part of your national organisation (for a small fee) and have our teachers education validated by the international HQ in the US. This is pretty much how it works now - also for such organisations as Scientology. So how come it should be different when it comes to the Aikikai.
Aikido is a japanese budo. The "original" origins of it in china/India/other places aside. So let's accept that Aikido head quarter - for now - is in Japan, and let's get the best out of it. It's an organisation, and those that participate actively get a saying. Yes it's inconvenient that it's in Japan (assuming your not living there) but that's just the way it is.
And to all of you that - discretely - claims that US probably have far more and far better aikido instructors than any other place in the world: Guess what.. It might be so, but until you have proof thereof please get down from the high horse and pull in the same direction as everybody else. Being part of something big is not necessarily a bad thing, You might enjoy it if you embrace it.
I'm no longer an Aikikai affiliated person (haven't been in 16 years or so), nor do I currently practice aikido anymore. From following conversations in Aikiweb in the past few years, one would have to recognize that Americans have been pushing for reasserting "aiki" into aikido. I'm not looking to turn this thread into a debate over that, but arguably Americans are trying to better aikido by returning it to what some might consider its roots. There is of course institutional inertia working against them, as it doesn't seem like the honbu overall is advocating for change.
What are the benefits of a large organization? Well asides from conferring rank and standardization, both of which have their merits and faults, the main ones to me would be networking and leveraging of resources.
Networking would certainly allow for one to train elsewhere or utilize relationships for the exchange of information. For a rank and file member, how much benefit do they gain from leveraging of resources? That to me is questionable. Perhaps, it allows for organization of large seminars or bringing over big named instructors or some combination thereof, but to a rank and file member there are additional monetary costs (seminars usually aren't free by big name people), and the question then becomes how much face time do they really get during such a seminar? Standardization is beneficial to some extent, as much like a McDonald's franchise, you can walk in the door and pretty much know what you are getting (portion sizes and some additional menu items aside, McDonalds in Japan and Germany taste much the same as in New York City). On the other hand, it can stifle innovation and evolution of an art, unless those at the top allow for change.
Now one could leverage the resources of a large organization like the aikikai and start some sort of standards committees to investigate various changes, much like the Japanese do in the tech world, but who knows if Budo is ready for that, the Americans seem to be, and I have no way to speak for the europeans.
From a personal perspective, my experience with large budo organizations has been almost exclusively negative, but I probably don't have the same experiences as the average martial artist who walks into a dojo which has a large national or international affiliation.