I would be inclined to make almost exactly the opposite statement.
Please, explain your statement, and where you believe those techniques come from and what their usefulness is.
As Ellis Amdur suggests in his book, Hidden in Plain Sight, one thought is that these locking techniques were put together by O-Sensei as a form of conditioning for the body to prepare it to better generate internal power.
I am not saying that these techniques, or at least some of them, might not have some self defense application. Variants of these techniques are used all the time by well trained law enforcement personnel. However, the thing to remember is that typically the police are not dealing with trained fighters but rather not very sophisticated criminals off the street.
Could anyone honestly think that if two Shihan level Aikido practitioners got in a fight, someone is going to win using one of these kihon waza in a form that looks anything like what we do in a dojo?
Years ago, when I did some koryu training under Ellis Amdur Sensei, he made a comment about some basics in one of these styles. he told us that it wasn't as if we studied these techniques with the expectation that we would use them to defeat an opponent. The practice was really to develop an understanding of how these basics worked so no one could do them on us.
These techniques originally had different origins... Ikkyo had to do with sword taking. Sankyo was a knife defense technique. Nikkyo occurs most naturally and easily as a weapons retention technique, etc. However, as nearly as I can tell, in their original form there was simply no execution without first applying atemi. In extreme situations, the atemi alone would be the technique. Shioda's story of being cornered in Shanghai during the war by some Chinese intent on killing them is illustrative... the first guy through the door got a broken bottle in the face and the second guy threw a kick and Shioda broke his leg. That's all atemi waza.
Jason DeLucia is an mma fighter with the strongest Aikido background. I have a very nice set of dvds devoted to application of various Aikido techniques in an mma setting. But if you watch his competitions against other professionals, the essential techniques of Aikido are no where to be seen. That's because you generally can't pull them off against another professional.
Anyway, you can see the versions of these techniques in aikijutsu from which our Aikido techniques derived and they had very specialized applications, almost always involving weapons, since the samurai were pretty much ALWAYS armed.
It would be my belief that these techniques, in their kihon form, were for O-Sensei, different variations of physically describing what he saw as the essential movements and energies of the universe, William Gleason Sensei does some good explanation of this in his second book, Aikido and Words of Power: The Sacred Sounds of the Kototama
in which he shows how various Aikido techniques embody certain energetic principles of the kototama.
Anyway, all this is just my opinion... it's fine with me if folks believe exactly the opposite. But I would suggest trying it out. If you can find someone who has an equivalent level of skill in karate or wing chun, muy thai or whatever, someone not an Aikido practitioner, and see if you can get any of these basic Aikido techniques on him. If you can do so without getting knocked out, you know something I don't know... which is certainty possible. Many people know all sorts of things I do not.