WARNING: The following contains spoilers for Fantastic Four #16, by Dan Slott, Sean Izaakse, Marcio Menyz, and VC's Joe Caramagna, on sale now.
Even though it kickstarted the Marvel age of comics, Fantastic Four #15 revealed that the Fantastic Four's first adventure had some sort of societal effect on the world of Spyre. This world was the original destination of the team's initial interstellar mission, which they never reached since they were derailed by the cosmic rays that gave them their powers.
Unfortunately, this was not unseen by the people of Spyre, who reshaped their world and culture accordingly. Now, the society of Spyre is extremely xenophobic, against supposed invaders such as the Fantastic Four or even their own people.
The world of Spyre bore witness to the Fantastic Four's first attempt to reach their world, as well as its aftermath. Believing the quartet were intending to invade on their exploratory mission, the Fantastic Four's resulting mutation and powers made matters even worse. Reed had first tried to enter the world after a scan of it revealed that its atmosphere would be safe to breathe in.
Unfortunately, the rulers of Spyre saw this information as making them vulnerable, and further bolstered their fears. The planet's citizens believed that the "arrogant Earthers" were trying to invade their privacy or even their planet—benevolent or not, any unintended outsiders could disrupt the "perfection" of Spyrican society, which extends to the Fantastic Four on their second arrival. Not only do Spyrican heroes The Unparalleled attack the team, but even after the FF prove their innocence, the Unparalleled attempt to kill Sue and Reed.
To combat another invasion from the newly superpowered Fantastic Four, the Overseer of Spyre harnessed cosmic radiation to use on his own people. This had the effect of empowering many of them to repel against alien forces, but some were not so lucky. For every Spyrican who gained fantastic powers like those of the Unparalleled, several more reacted disastrously toward the radiation. Spyrican society not only hates outsiders, but cares little for its own citizens who no longer fit in the model of perfection.
Those who did not gain incredible powers through the cosmic radiation were instead, like the Thing, horribly mutated into hideous, grotesque monsters. Due to these disfigurements, these monsters were promptly shunned from greater Spyrican society, and forced to live in the underbelly of an otherwise supposedly "perfect" world. This strict adherence to their idea of perfection exists before the Fantastic Four's first brush with the planet, but their attempted arrival only reinforces the prejudice and oppression of those deemed inferior.
Big King Skrum, a prominent villain on Spyre, is the leader of the mutant horde, despite once having a family. Due to being outcast from a world that they were once firmly a part of, these monsters resent the other Spyricans as well as the Fantastic Four, who they blame as forcing them to have to undergo the process that mutated them in the first place.
While the effects of cosmic rays on Spyrican society prove that the effect they had on the FF can be replicated, it also shows how disastrously the aftermath of that exposure could've played out. Even if the FF never really had trouble embracing the Thing just as much as any other member of the team, the FF will still have to deal with the unintended consequences of their origin.