There can be a "place for pain" in Aikido training in terms of helping people understand that in any "self-defense situation" one may very well get hit, bruised etc. in any encounter. If that experience impacts them enough such that they cannot stay present, then it can be a good idea to work with that process at a certain level so the person can get accoustomed to the experience so they can deal with it in real life. But that is a completely different aspect than what this thread is about, as far as I understand it. I'm talking about the application of Aikido waza.
I don't think we are so different after all.