Re: Why do we do it?
My current skills might not prevail in a fight. Or they might. But just because they did not would not be a blanket reason to condemn Aikido as ineffective.
Let's make a baseball analogy.
The pitcher throws, the batter swings. If the batter misses, was the batter's baseball ineffective? If he gets a hit, was the pitcher's baseball ineffective? If the fielders don't catch the hit ball, is their baseball ineffective?
You can say that all the practice a pitcher has put into baseball since he was a child, and his current skills and fitness, were not enough to prevail that time against that batter. Is that a reason not to practice?