Really, these people want to stay on the island? Having to pee outside and eat coconuts forever? Don't they miss steaks and Krispy Kremem donuts? The Dharma Flakes cereal alone would make me start paddling out to sea.
Also, is this island really the planet that regenerated Spock in Star Trek III: The Search for Spock? Did anyone notice the island in the picture in the psych ward in the Hurley episode last week?
People want to stay because they are getting what they need from the island. They are becoming strangely complacent about the past threats because they are fading in their memories (exceptions: Ana Lucia, Michael, Bernard) and they have a lifetime supply of black and white label cereal. It's the perfect mousetrap. Dharma Flakes....mmm, mmm good.