In many forms of entertainment, one has to suspend belief in order to enjoy the show. This is different than suspense, which is the creative choices to lead a viewer down a path of twists and turns to a climatic end. This is part of the creator-consumer bargain.
To suspend disbelief temporarily allow oneself to believe something that isn't true, especially in order to enjoy a work of fiction.
First, was the survival of a mid-air plane separation at high altitude. It is highly remote that anyone would have survived a terminal velocity fall into the ocean, beach or reef. But we accepted the premise that several people did survive the plane crash in order for their stories to move forward.
Second, was the appearance of a "smoke monster." All supernatural things are unknown in our daily lives so we must forget reality and accept that monsters can exist in our entertainment world.
Third, was the mysterious "healing" properties of the Island. Rose was cured of her terminal cancer. Locke was cured of his permanent paralysis. We must accept that miracles can happen, just as in Jack's backstories about his miraculous spinal surgery results.
Fourth, that the island was a) unseen; b) moving; c) had strange light properties; d) was surrounded by some type of snow globe barrier, and e) disappear without displacing any ocean water. The acceptance of something unworldly and defies natural laws of physics begins to stretch the supernatural aspects of the story. But some people can buy in to the premise that the Island is not a island in the conventional sense.
Fifth, that characters meet horrific deaths but somehow come back to life. For example, Mikal (Patchy) had more lives than an alley cat including incineration by the sonic fence. Sayid was dead but somehow was resurrected at the Temple.
Sixth, that Desmond could have survived the Hatch explosion-implosion, then survive the megawatt EM shed which fried a workman. The ability of a human to transform into a superpower being is standard fare in action science fiction comics.
Seventh, that there is an unknown element called the Light Force which represents "life, death and rebirth." And that this force somehow needs human intervention and protection in order to survive.
Eighth, that human beings can "create" their own purgatory to have happy reunions in the after life. Modern religion conventions seem to state the opposite.
Ninth, that an unknown entity that can shape shift, capture memories of the dead, and take human form can be killed by a rifle bullet. The smoke monster attacks on islanders was vicious and unstoppable. Sayid could not kill Flocke in its human form. We have to believe "something" changed to allow Flocke to die.
It is fine that the LOST mythology presented various aspects of our existence which we, as viewers, had to suspend our current knowledge, experience, and beliefs, in order to accept the story. But each of those belief suspensions now have to be taken with a grain of salt.
It is fine that writers create situations where they ask you to suspend your beliefs to go forth in a science fiction or supernatural world. But it is also the writer's responsibility to educate or explain why you should take that leap of story telling faith. In the above examples, the TPTB did not explain their fictional basis for any of these major plot points. There was no explanation of how these plot points could exist in the LOST world. There was no explanation of why these plot points were important to our understanding of the characters or the story arcs. The writers never tied these plot points together to explain any of the island mysteries. Strange twists left hanging is like staring at a clothes line on a windy day.