Re: Dojo loyalty or personal gain?
I had a teacher (not in Aikido but in another area where teacher/student relationships are important) who was awesome with beginners: she could take a newcomer, teach them the ropes, nurture their talents and get them to quite a good level. I learned a lot from her. Then we had a terrible falling-out and ended up hardly on speaking terms.
We were both part of the same organization for over a decade, and I got to watch her go through this same cycle with three more protegees: wonderful relationship at the initial level, horrific breakup later on. It seemed to me that at the point where the student started to develop her own opinions and style, and to disagree with her teacher and back up that disagreement with actions, the relationship was inevitably doomed.
The teacher didn't see it this way, though: she kept feeling that if only she got the right student, she'd be able to maintain the relationship.
We eventually asked her to leave, because the whole thing was getting too painful, and her feuds with her ex-students too disruptive. It was sad: she really was an excellent teacher up till the point of no return.
I wouldn't be surprised if the same dynamic goes on in some aikido schools. I wish I knew what to do about it; we never found a useful approach.