Like I said at the most simple level. I did not mean uke should actively seek to throw his balance away and yes, without a sincere committed attack what does Tori have to work with.
By the way - in my view once uke can actively resist and counter then the distinction between the two (tori and uke) becomes blurred.
Hey I was playing devil's advocate. Why would someone answer no to a question where the author expected a 100% yes response. Again in my view we should train as hard to be good uke mainly because tori then has a chance to maximize a technique's execution when you are uke and hence you can make the same demand.