Soft and hard
Sometimes in discussions on what kind of aikido works or not, I get the feeling that we talk about different forms of aikido that should not really be compared.
There are, of course, many ways to train aikido, and I strongly believe that it is good to try more than one of them. Such as gotai and jutai, for example. Gotai is from a static position, where uke is expected to grab hard and use some resistance, whereas jutai is in movement, where it might actually be dangerous for uke to resist or try to stop the technique.
There is also a very soft way of training, where the principles of rhythm and flow are investigated further. Many of the performances that make spectators very doubtful are of this nature. But in that kind of training, uke is supposed to accept the impulses felt through tori's actions.
Still, it is very meaningful training, since it leads to a deeper understanding of subtleties at work in aikido. Simply put: your gotai technique will get stronger by it.
Also, I think it's important to understand that aikido people easily go into ukemi, when they get out of balance. People without such training would stumble around instead, or just collapse to the floor. So we should not expect every ukemi in aikido to be the result of a mighty force from tori, but as a safe and natural reaction in uke.