Wow, and I thought -I- tended to the lengthy posts *grin*
In any case, DMV, you've got some interesting points that need addressing. I agree that many people might have some kind of opposition to striking due to some percieved aggression that is inherent in a strike, and not in a throw... although I think they would categorize it as disharmony, rather than agression.
I don't entirely agree with throws being inherently more deadly, though. More likely they were favored on the feudal battlefield due to considerations of armor. If you punch a heavily armored man, you will accomplish not much other than hurting your hand. If you apply a joint lock, it will probably still work.
As for the "can't any kind of technique be done softly", well, no, they can't. You simply cannot subdue someone by punching and/or kicking them softly. If you're really skillful, you may be able to subdue them by throwing them softly, then pinning them.
However, this may be a false dichotomy. I believe (and this one is going to cause some uproar) that when O Sensei was talking about not harming your opponent, he was talking about not killing them, or doing any -permanent- damage. Given how hard he was known to throw people, they may have found it to be more merciful to be knocked out with a quick fist to the jaw.