If you were living on a planet, and a ship landed with beings on it who told you they were now the government and you were obligated to live according to their opinions, would you?
If they killed to discourage disobedience would that somehow make their claim legitimate?
So, why do people believe the same lie when it's members of their own species (supposedly) making the outlandish claim?
Their claim doesn't even make sense- it's nonsensical from every angle- so they can't prove anything. Yet, instead of laughing and defending themselves from these parasites, people let themselves be bullied.