There has been a resentment in some circles to how LOST was structured as a series. Many people believed that the writers merely threw plot twists, traps and mysteries against the wall to see what stuck in the hearts and minds of the fans.
Humans have the brain capacity to be curious about their surroundings. We have the intelligence to apply knowledge to problems to find solutions. That is why we are at the top of the food chain. And that same basic mental framework is how we view our information and entertainment.
Even before we can walk, as babies, we want to put the shaped blocks through the right holes and into the bucket. That is why a few of us still continue to think whether there is (by accident and not even design) some unified explanation for the layered, complex and engaging story lines of the series.
Or, do we have to come to the final conclusion that we were duped by a canvas of splattered paint instead of coherent statement of words and actions.
The unease comes from the fact that many of the major themes and consequential moments (at the time) were rendered meaningless, irrelevant and immaterial in the conclusion of the series. For example, could the castaways gotten to the sideways church without the smoke monster story lines? Apparently so. What did the island time skipping have to do with the reunion in the church? Nothing. Did Juliet set off the bomb? It did not matter. What happened to all the deep and detailed ancient Egyptian ritual and hieroglyphs that expanded in scope as the last season unfolded? It turns out to be mere artful misdirection.
That is why so many people cannot grasp the significance of the ending because it was not foreshadowed by any of the action of the main characters. It was an off-ramp to a quiet side alley when the story was a super highway rushing to the final toll booth of answers.
All art, including storytelling, can many different variations. It can be mystery, drama, comedy, surreal or even absurd. It is just like in fine art painting. You have those artists who use the medium to express realistic portraits, impressions, illusions to reality, abstractions to comment on life, to surreal merger of mismatched items like a Dali creation to shock to viewer into wonder and personal reflection.
As I said above, a criticism has been that the LOST writers were merely throwing plots on the wall without any reason or structure in order to move the series forward. In the art world, this splatter approach was made famous by Jackson Pollock, who spilled, sprayed, flicked and tossed random colors on large canvases to make his art. Some people adore the freedom of expression, other people hate it as a mess, and many are just indifferent with the result. Sounds a lot like the reactions to the end of Season Six.
The strength but also the problem with the Pollock drippy style is that is it is "easy." It is easy to create because it is abstract. The result is all in the eye of the beholder. The artist does not have to say anything about the subject matter (even if there is one in his own mind). There are no rules. Structure is abandoned. Convention set aside. Recognizable symbols or shapes are not used to convey any message. I did the above graphic in a matter of minutes. If 100 people look at it, you would probably get 100 different responses to it. It is both nothing and anything. I had no concept of what I would be drawing; I only threw dashes of color and lines on a blank piece of digital paper. To me, it is just an abstract drawing.
To viewers of LOST, they do not want to see their show as an abstract nothingness. They were led on so many paths, experienced so many key moments to have the final reveal to be a Pollock-style painting. That is why a few keep searching for the hidden brush strokes.