They told us "No."
If they had taken the time to learn about us, to truly understand what it was that made us human, they would've known that that had been their greatest mistake.
Sixty-seven years ago the Qash'vo'tar conquered Earth. Ever since then, the aliens had ruled from above. The Qash'vo'tar did not care what humanity did on the ground, as long as they didn't attempt to build anything that could get them to the stars.
Instead of the stars, humanity explored the oceans, burrowed deep underground, and broadened its understanding of laws of physics. Until finally they could take no more. In secret the United Earth's best scientists attempted to find a way out. Deep underground, they created a portal to another universe.
They made a breach to a universe where there was magic. This new universe changed them, changed their own universe. This one accident gave them a new weapon against the Qash'vo'tar. And they studied it, integrated it with their technology, and they waited for the right time to strike back against their alien overlords.
And now, sixty-seven years after they had been conquered, it was time for humanity to show the Qash'vo'tar that they had been right to fear humanity.