Re: It's getting annoying..
I don't know you, and I don't know your dojo, so no need to make comments on your character or the quality of teaching over there.
But there are two cases in my experience, where we were in a very similar situation.
1) The teacher of the dojo I join in Turkey virtually started from scratch. He founded the university dojo at Istanbul Technical University when he was shodan, and since the dojo was new, and the only one at the university, all students were beginners. So for some years he only worked with beginners (except seminars, and in Turkey they are not so frequent as here in Belgium) and educated his ukes. That was some seven or eight years ago. When I first came to his dojo, he had already one yudansha and ten or so advanced kyus. When I go there now, there are four or five classes per DAY, for small kids, advanced kids, tanto/ bokken, beginner adults, advanced adults, you name it. It cost him some years, and a lot of time, but finally it worked. So, there are no good ukes => you start producing them, and some day you'll have them.
2) In my dojo here in Belgium, all advanced students dropped out when the old sensei quit due to health reasons. Most of them went to a neighbouring dojo, and only us (4th kyu and lower) remained. Another teacher took over; he had some "advanced" students, but still there were very few hakamas on the mat. That was three years ago. No we have a 2nd dan, who joined from outside, and apparently we were not too boring to train with, so he stayed, and all the "old" aikidokas advanced, so there is always someone advanced to train with.
This said, I always have perceived it as a honour to be found good enough to teach beginners. If I don't know anything, I can't transmit anything. So if the teacher trusts me enough to let me teach beginners, I see it as a compliment, but also as a responsibility, and actually I even enjoy it. We have two classes where most students are beginners, and two classes where most students are advanced. I go to all of them, and I think it is interesting to work with beginners
=> they attack differently (they are not yet formed in the aikido mould), so you have to be more flexible
=> they don't know the movement very well, so you have to be slow and precise. That improves also your own techniques.
=> sometimes they are quite observant and tell you about an error you never found out yourself...
And in case its getting bored, there are always seminars.