Why do the sailors at first chastise the Ancient Mariner and then approve his killing of the bird? Why do they then accuse him once more?

The sailors initially accuse the Mariner of taking their breeze away by killing the Albatross. The great bird is supposed to be a good omen. Then the sailors praise the mariner because they think they were being led into mist and snow. Then when they get iced in, they once again accuse the mariner of casting bad luck upon them because he killed the albatross. They just can't make up their minds!