In the end, it's just a Japanese dojo, catering to people living in Japan, specifically Tokyo.
Edit: And yes, I personally try to learn to speak a little of the language of every country I visit.
I have mixed feelings on this issue. Of course it is always good to speak local language. But Hombu dojo is not an 'average' dojo in Japan, it has a very special status - International status. Doshu is a head of this dojo. Me and many hundred thousands aikidoka have his endorsement on diploma, and he is very happy to receive a lot of money from all over the World for that. And not only from the students of Hombu dojo. It seems to me that some kind of balance should be created as we are also supporting him.
If ppl feel ignored during their visits in Hombu dojo, already very thin link to Doshu can be very easy broken. They may stop asking diploma from Japan. In this case Hombu dojo may really become an 'average' dojo in Japan. But I'm not sure if it will be a good solution....