The Answer was Purgatory from the Beginning by halloweenqueen

First...I use the word Purgatory for lack of a better word.

One of the best things about LOST has been the community that grew from the very beginning. The forums, blogs, and podcasts were a rich environment for theories. What made it even better was the participation from the very people who brought us LOST. Damon and Carlton were a great resource in expanding our LOST universe.

One unfortunate thing to come from this might have been we spoiled LOST very early on. Many viewers predicted the Island might be Purgatory and our Losties dead. The first season, in particular, seemed to point to this possibility.

Damon and Carlton were quick to say the Island was NOT Purgatory. How could they admit we, the viewers had spoiled it? Of course they couldn't come out and admit that "we" had figured it out...so how to recover the story?

I think they changed course with the flashforward and Oceanic Six storyline in season four. After that it was hard to explain how they call could be dead and yet "leave" the Island. I think they hinted they still could be dead with the idea that the plane was really at the bottom of the ocean.

The ALT universe was created so they could end the show how they entended from the beginning. To tell the story of these group of Losties and their eventual redemption.

I wish they would have stuck with the Island as Purgatory. That idea would have made more sense and brought more closure to the story. The story would have remained ON Island (saved us from all the Oceanic Six nonsense) and brought the story to the heart of what most viewers held dear....the story of our Losties ON the Island.