I voted 'no'; it's easy to see someone's problem (e.g. resistance, straight arm) and then do some attack; however there is no need to be drawn into uke's violence. Often I am pleased with those in randori who do not do a technique, but end up avoiding the attack. Trying to 'do' a technique is the curse of aikido, and self-defence. However, it does get frustrating if uke repeatedly does not give a committed attack, though I think this is usually just a lack of attack training. Also, I am of the opinion that uke is just a live training dummy, not a competitor.