I believe that we tend to confuse a sincere attack with intention ( a training tool) with a competitive attack such as exists in various styles of free-sparring in other MA. In most free sparring there are no defined roles of attacker and defender, both are trying to score, defeat, win, knockout (choose your own ending) and therefore the dynamics, both physically and psychologically, are very different than classic aikido keiko, It is quite possible to overcome a training partner who is waiting for you to launch an attack, especially when the partner has agreed not to preempt your attack and has agreed to do minimal damage when executing the technical response.
I practiced full contact Chinese Boxing (Chuen Shu Chuan) for almost 8 years, and although we hit each other fairly hard (bone fractures and breaks were not uncommon) we still held back for 2 reasons, we were not trying to destroy each other, and we were very conscious of possible escalation to a dangerous point.
I often think that aikido could benefit from free sparring, but in most cases it would degenerate into some form of wrestling or unskilled shooto, and part of the character of our training would be lost. Most of the older practitioners (myself included
) would bow out, since our physical recovery time after injury would become prohibitive, and there would definitely be injuries.
I have to agree with the "unpronounceable one" concerning shomen uchi. After almost 7 years of Shinkendo, including much tameshigiri, I believe that an unarmed person stands less than 1% chance of surviving against a sword. However, if the swordsman were stupid enough to raise their sword to jodan then perhaps. Defending against a swallow cut begun from kiriage is impossible. But whoever suggested that we were doing anything other than training our faculties to a better appreciation of maai and timing when we use weapons. And who confuses using the hand for using a sword?
Likewise, who amongst us really confuses the notion of a sincere attack with the idea of learning how to "fight"? If that is what we seek then we should start to modify all our attacks to mimic real attacks, wear body armour, incorporate scenario training, including psychological stressors etc. Show me the way out please.