My 2 cents worth.
If you get into a fight, there's only a small chance you will win since there are millions of people out there that are better than you physically.
In order to have higher probability of you coming out of a fight in one piece, the point of Aikido/Aiki I think is to remove "YOU" and any part of you(regarded as weak) from the picture entirely and totally rely on/utilize the natural forces to be on your side when a fight ensues. When I say natural forces, it is the physical laws (ie gravity, use of levers, conversion of potential energy to kinetic, zero work, etc.) where all masses no matter how big or strong will succumb to these forces. That is why even a small person can control a very large person if he has good understanding of the physical laws and how to use these to his advantage.
The more "YOU" get in the picture, the lesser Aikido you are doing and the weaker you become. IMHO, you are just the "medium" neither attacking nor defending but you have something more powerful on your side you are using to control uke. If you start attacking or defending, then Aikido's potency will be diminished since part of "YOU" now will come into the picture. Maybe Osensei said Aikido doesn't have enemies because everybody succumbs to the natural laws?
Actually that statement is useful for a fighter. When mentioning O'Senseis quote and thus Aikido I would say quite the opposite is true regarding less you. (less ego, yes)
In other words as you understand more the universal laws and become imbued with them then you actually become more you.
In becoming more thetrue you then you become more and more in tune, stable, in harmony with whatever is in front of you no matter what it is or what it's doing.
Thus you realize that the only one you were ever fighting was yourself.