Why did the In-Between appear as an Island-free Reality? by Hot_Pocket

Why did the In-Between/Limbo/Purgatory exist as an Island-free Alternate Reality?

Forgive me if this has already been addressed; this is the biggest question mark I had walking away from Lost. Here's my interpretation...

*Widmore, Jacob, Mother, etc have all been saying that if the Island is destroyed, it will result in the end of the world, the end of all life.

*When Juliet detonated Jughead, an Alternate Reality was created, splitting off from the Original Reality (where Jack and Desmond ultimately kill the MIB, replace the cork and save the Island - that was all real) On another plane of reality - Oceanic 815 never crashed, Desmond & Juliet, etc. never went to the Island, Ben never slaughtered Dharma - because Jughead had sunk/destroyed the Island (as we saw in LA X)

*However, since no life can exist if the Island is destroyed, this Alternate Reality can only exist on a spiritual, meta-physical plane: Limbo / the In-Between / Purgatory. That's why this version of the Afterlife plays out as if none of the characters had ever had their lives affected by the Island. The Losties must embrace their former reality where the Island existed, its Light existed, and their physical lives existed - before they can move on.

The detonation of Jughead was the Losties ultimate refusal of the Island, Jack & Company sought to utterly erase it from their lives. That's why Christian tells Jack that this realm is "a place that you all made together". In the end, when the Losties finally remember their original reality, they remember the Island, and they ultimately accept that the Island was their destiny, not their curse.