TL;DW: The theory follows two statements from Steel Ball run, Infinite Spin is an endless ever rotating attack and The shortest path is a detour so the infinite spin will reach its target no matter what.
These two statements combine with the metaphysical meaning of Gravity in the Jojo universe. Infinite Spin contain infinite gravitational energy and Gravity is key force controlling fate, time and all connections in the multiverse.
When Johnny used the infinite Spin to try and destroy his son’s disease brought on by Calamity logic, he missed, was struck by Calamity and his Infinite rotational gravitational energy entered the very earth of Morioh. From then on this Gravity manipulated fate and society and time in such away to create this long detour chain of events to result in the birth of Gappy, the only character whose existence is outside of the logic of Calamity so he could have the chance to manifest the infinite spin but this time as a “non-existent illogical Spin” that Calamity cant make miss.
Hence the “Single Attack” from over 100 years.