For a long time, the fitness of humans had been nowhere near the heights of the shura. But humans strived to be better.
Generations after their first meeting, the gap in talent between the two species was still unbridged. But then came the discovery of the sanctuaries, and after this, humanity accelerated in strength as if they were cheating. While it did not change the average human, human elites were capable of becoming stronger than the shura.
Kids and teenagers were still particularly vulnerable, being far weaker than the shura.
Humanity had many goals, and the humans of this universe wanted to develop their kids and teenagers until they were naturally superior to those of the shura.
It was a common desire, shared by not only the average, working citizen but by the high-ranking officers of the Alliance, as well. The latter of which were actively working towards it.