I agree with you about uke giving you the info which "should" decide what technique "fits" that spot in space and time and demonstrates the universal riai of the instant.
However, if the skill levels are different enough that the defender can "overwhelm" the attacker or the uke in practice is not taught to challenge/and or counter his partner when possible, the tori can force techniques to fit.
Of course, the real problem with forcing the situation is: You have to make a decision about what to do. I don't know anyone who makes the "right decisions" all the time. If we follow principle properly, the dynamic forces at work in the action tell us what to do. If we (as you suggest) listen and just "take part" in rather than "control" the event, it'll always be intuitively creative and fit what needs to happen.
Whew, long sentences, eh?
Kata is meant to teach us principle which gives us the ability to make those intuitive, creative decisions which show true riai. There's a saying that what happens in kata never happens in a real combative situation but kata gives us the "tools" to survive the reality.