Fall of the Mind Fleet was always a celebrated event across the Cosmos as the Mind Flayers were hated by all, probably even more than Orks or Arachnid Swarm by a great degree. That just affirms how much menace they were to civilized space and civilization, star-faring nations.
Still, the Mind Flayers were a really powerful species that had a certain degree of right to do what they wished because that was like things functioned in the winner Cosmos. The stronger fed on the weak to get even stronger, and there was no mercy.
If someone wasn't powerful, then it ended there, and nothing else could be done.
It was also one of the reasons why all civilizations so desperately tried to cultivate more and more powerhouses to protect their borders, interests, and, in the end, also their very own existence and fundamental right to even exist.
Without power, the person was just an insignificant speck of dust on the tapestry of stars; anyone could fall.