I think we're talking about two different things -- one being; should practice in the dojo equate that of street combat? I think the general consensus has been a comfortable 'no', unless some folks are training in alleys and grabbing trash can lids or car attenas to strike with as uke
The other one, which brings us back to the original issue, is; do you attack with intention? I think another worthy question is; do you comply with the technique? And not because someone's legitimately taken your kuzushi, but because it's polite to do so.
I believe uke's attacks should be measured to the skill level of nage, but should always have intention, meaning nage is going to get struck/grabbed/shoved/etc. if they don't perform the technique. The actual impact can be as light as a tap for a beginner, or at the very least, sufficient to cause pain if it's a yudansha. The point being, nage must give sufficiently honest 'attention' to uke's honest 'intention' to honestly develop in their aiki training.
Going along with this, when nage is a beginner, I think it's helpful for a skilled uke to move through the technique with them so that they can find its shape. On the other hand, by yudansha level, such compliance takes away from the integrity, I believe, of the aikido training. I'm a former wrestler/judo player and have to fight to not use muscular power in the application of technique. If someone's going along with my application without my having taken their balance, then my learning is impeded twofold. First, I'm not learning how to redirect their center. At the same time, I'm relying on brute strength for my aiki, which I think is a bit of a contradiction.
Just my opinions, of course.