Dirk Hanss wrote:
Whenever I did such an exercise, it was mostly a pure ukemi exercise, i.e. the jo was used to support your ukemi, not to enforce it.
For tori, I have seen that kind of training as training in handling stress. Compared with several attackers who come from whatever angle they choose, in this exercise focus can be put primarily on timing and on... well, handling stress. I am sure it can be done with many different purposes, though.
I agree it sounds like the instructor could be more clear about what it is he wants and does not want in such an exercise.