There is a reason why the Gorgons did not react to the provocation of the Angels. They are too focussed on the execution of their own plans. And that includes first and foremost to create division amongst the humanoids. So that they will not rise against the Gorgons too, or join the Angels in their resistance.
The Gorgons use their Prism-technology to appear at the humanoids and profile themselves as Gods. In order to create confusion amongst believers and non-believers. On the first day they single out a few separated believers in the supernatural, appear for a few seconds and then disappear, without saying a word.
On the second day they appear for the non-believers. People with a firm believe in science and technology and no or little room for the supernatural. Again a Gorgon appears for a few seconds, then disappears without saying a word.
And on the third day a Gorgon appears in the improvised temple the humanoids are using for their rituals since they arrived. "Your technology has destroyed your home planet. Chemical warfare and industry have chased you away, looking for a new Eden. Now you have come to this pristine planet we created. And we are making you the keepers of it."
Then on the fourth day during a celebration a statue descends from the heavens in the improvised temple. On its pedestal are written the following three commandments: "This planet is your mother. Therefore: Thou shalt not harm the planet or any of its creatures. Thou shalt worship us Gods, and us Gods only. Thou shalt not use technology or science."
Three days later, in the base camp of the engineers, a statue has been raised in the middle of the camp. On its pedestal is carved "Thou shalt not use technology or science."
This last incident with the statue in the base camp of the engineers is the proverbial straw that breaks the camel's back for Mac, head of the engineers, and he confronts Zoroaster.
Zoroaster is the leader of the believers. The moment Mac starts talking to him, more people join to backup Zoroaster. Mac tells him that the intimidation of the tech people has to stop. Zoroaster replies that they are only doing God's work.
After Zoroaster and his followers disappeared, an Angel appears to Mac. She tells him her name is Ariel and that she means him no harm.
Ariel tells Mac that she has been observing his species for some time now. She warns him for the false gods, and explains that it is an old species, the Gorgons, who are technologically advanced and use this to submit younger species. She also informs him that there is a long feud between her species and the Gorgons. Mac listens carefully and is immediately charmed by the personality of Ariel.