DCP

Appropriateness of resistance is the important factor to consider. I have worked with many uke who know what technique is to be done, and they resist the technique physically with all they can muster to stop technique. They stop the technique and they glow with the "I win" attitude. It's actually quite easy for uke to stop technique when he/she knows what's coming, but that isn't necessarily martially beneficial since openings are often present in uke.

Uke's ego comes to play here. It seems some develop the "Ha-ha, you can't do the technique" attitude. There have been times I've changed technique when uke resisted, and I become the bad guy because "That's not what Sensei demonstrated!"

Intent of attack is also an important factor. It is hard to blend with energy if there is no energy. For example, I've worked with several uke who perform "Statue of Liberty Shomenuchi." This is where uke steps forward to perform shomenuchi, but their downward cut stops short of hitting me, and they leave their arm stiff and static above where my head would have been. This is an inappropriate example of physical resistance to technique.

I guess I am echoing some previous posts, but with examples. Lower-kyu aikidoists probably shouldn't resist techniques due to lack of intent, not understanding openings, and higher probability of getting injured. The problem is that lower-kyu aikidoists need to shed the "I win" attitude.