The internet is a wonderful attic of miscellaneous information. In one cobweb corner resides other lost fan theories that were compiled over the years. We will review a few of the most interesting ones.
Fan Theory: The Dharma Initiative is using the island as a "sort of human recycling plant," taking "damaged, fallen people" and either rehabilitating them or junking them. And the Smoke Monster is the quality-control mechanism in this factory, testing people to see if they deserve to live or not.
This theory must presuppose that the world will have a bleak future where resources will be very limited and death panels will need to segregate who should live and who should die. In the 1960s and 1970s, there were academic and political discussions about world population growth and increases in starvation in third world countries. "Zero Population Growth" was the buzzword in advanced industrialized countries, whose birth rates today have plummeted to below replacement levels (which has caused the unintended consequence of immigration friction).
This theory also has the feel of a post-World War III reconstruction. In Europe, Nazi Germany had rehabilitation camps where people were sent to be "retrained" into nationalized policy citizens. In elitist and arrogant societies, those in control may perceive the lower classes as mere commodities or property to be discarded if they were "broken" or no longer served their purposes.
There were plenty of evidence to support this theory in the show. Dharma was powerful enough to create an elaborate series of scientific stations which mostly concentrated on the collection of data and manipulation of human beings. Room 23 was clearly a mind control facility. Other stations, like the Swan, were created to trick people into a certain mindless level of behavioral control, like typing in numbers into a computer every 108 minutes.
The one downfall of this theory is apparent. If the situation was dire, this island facility is too small to take care of the masses of broken humanity. Instead, one would have to look at the island as a prototype facility, to test the scientific theories of human recycling. The fact that early Dharma visitors "volunteered" like Ben's father to come to the island reinforces the notion that Dharma was preying on the weak or weak minded. Likewise, kidnapping professionals like Juliet to run experiments would show the ruthless above-the-law arrogance of corrupt political elite.
The other problem with this theory is that by the time 815ers crashed on the island, Dharma had been dethroned from power. The Others or native people were in charge of the island and its facilities (most were closed). The Others had no reason to continue Dharma's work. The 815ers may have had their individual personal issues, but they were not collectively "damaged" beyond repair.
And as an origin story for the smoke monster, it tries to make the advanced technology of Dharma as being the manifestation of the "evil" that Dharma would have represented in its hey day. However, with the ancient hieroglyphs contained in the temple and island monuments, the smoke monster appears to be older than Dharma - - - that the smoke monster was already present on the island when Dharma came to build its facilities. Whether Dharma "captured and trained" the smoke monster to do its bidding would be the subject of debate, because we still don't know whether Smokey was an animal, an alien or evil incarnate.
The "testing" of individuals may have been a way of getting around the purgatory theme that the show's producers denounced early in the first season. The concept of "testing" souls is also part of the Egyptian religious rites. The theory that damaged souls have a chance to "redeem" themselves before dying is a new, secular concept. However, there appears to be more gray area in the LOST story lines than black and white moral lessons.
This Dharma theory would have had a stronger argument if Dharma was still an active player when Flight 815 crashed on the island.