Re: People who are never uke
Since it was my comment I guess I should clarify it.
It is possible to develop such a grounded, stable structure that one simply cannot be moved. There are people that I can't move. There is a smaller group of people that my teacher can't move, at least not from a static position. There is a still smaller group of people that *his* teacher can't move. Having that kind of structure is valuable, and there are specific kinds of practice aimed at developing structure, and at being able to undermine another person's structure. I suspect that's what Carsten has in mind.
And, really, my statement still holds, it just requires a higher level of skill on uke's part. If *no one* in your dojo can stop your technique from a static grab, you need to train with better people because actually executing technique from a static grab by a grounded opponent is really really difficult. (Remember, though, that they may be *able* to stop you and choose not to because they are trying to help you learn.)
But that's not the situation I had in mind, and it's not what the OP seemed to have in mind. I'm talking about dynamic technique where uke is coming in with some amount of energy and nage is attempting to execute the technique demonstrated by the instructor. Except atemi is frowned upon by that particular dojo, and so uke simply doesn't respond to energy directed at his vulnerable points, and therefore doesn't make the turn or the rotation that the technique requires. And henka waza is also frowned upon, and so nage is unable to change to a technique appropriate to the position in which he finds himself. And, now he finds himself in the situation Carsten described, but without the skills to even begin to approach the problem because his teacher doesn't have a methodology for teaching him and his uke is too busy polishing his own ego to help. Complete waste of time for everyone involved.