With this X-mas thing coming soon and stuff, people are more inclined to believe in magic these days. So when they saw the Alien Pets falling down from the sky, everybody thought they were angels and started thinking of miracles. But they soon realized the truth, upon closer inspection. Everything was in favour of the second hypothesis: the green color, the UFO-like spaceship - it was clear they were aliens! So people didn't think that was interesting and left the place of the so-called "miracle". And we're stuck with the Alien Pets.