Takahashi identifies the core problem here not as some failure of technique or martial reality or some other external factor. Instead, he identifies it as a loss of understanding of an internal driver of Aikido, the taking of balance.
Unless I can out muscle uke, I can't throw him without taking his balance. Before I can take the balance of another I must first learn to establish and keep my own balance; of forces within me, of mind and body, of motion and stillness. One aspect of Ki development work focuses on enabling me to learn to do just that.
Technique practice is the proving ground for putting ideas into practice. Once I have mastered my own balance, I can use those skills to affect uke's balance such that doing so facilitates my ability to neutralize his attack and bring him to the mat via a throw or immobilization.