Kelemane's planet was an extreme example of cultural contamination
Another extreme case of cultural contamination was Sigma Iotia II whose entire society was based on the book Chicago Mobs of the Twenties
Ekos was a third extreme example of cultural contamination, whose society was similar to Nazi Germany
Cultural contamination was the alteration of a culture's natural development by an outside influence or exposure to a more technologically advanced society. Cultural contamination could be sociological or technological and could have drastic consequences.
Cultural contamination was a concern among warp-capable species at least as early as the 20th century, by which time a Vulcan team stranded on Earth hesitated to interact with the Humans. (ENT: "Carbon Creek") In the 22nd century, the Vulcans had adopted a policy of non-interference with less technologically advanced societies. (ENT: "Broken Bow") Under the guidance of Vulcans, notably T'Pol, Earth's first warp 5 starship, the Enterprise slowly began to adopt a similar policy despite initial difficulties like those encountered on Valakis. (ENT: "Dear Doctor") T'Pol referred to this policy as standard protocol and assisted in making decisions to ensure this protocol such as in 2151 when she chose a farm as landing site for an away team on the Akaali homeworld. (ENT: "Civilization")
Repeated encounters of this type eventually led to the creation of the Prime Directive for Starfleet, which prohibited interfering with any pre-warp civilization as well as strict rules for initiating first contact. (ENT: "Dear Doctor", "The Communicator"; TNG: "Homeward"; VOY: "Caretaker", "Time and Again")
Even so, incidents of contamination were not rare and both accidental and intentional occurrences have been recorded. Notable instances include the contamination of Sigma Iotia II by the Horizon, which led to a complete alteration of the social structure of the planet, and the intentional interference on Ekos in an attempt to correct perceived flaws in the society. (TOS: "A Piece of the Action", "Patterns of Force")
In the case of Kelemane's planet, the USS Voyager being trapped in the planet's gravitational pull, and the resultant seismic activity this caused on the planet's surface, lead the civilizations on its surface to revolve their development around Voyager, prompting the imagination of its people over generations, as a result of accelerated time on this world, inspiring the people to, at various times, view it as a deity, attempt to communicate with and observed the ship, prompting series of stories and tales to be written about the ship, and at one point to destroy Voyager to stop the seismic activities, before realizing that Voyager was in fact not malevolent, but trapped, by which time a successful attempt was made to help pull the ship out of orbit. (VOY: "Blink of an Eye")
Despite the dangers, the instigators of cultural contamination occasionally attempted to repair the damage by revealing even more about themselves, or making the society further aware of the changes that had occurred. One example of this approach was Captain Jean-Luc Picard's resolution to the contamination of the society on Mintaka III when a Federation anthropological field team was exposed there. (TNG: "Who Watches The Watchers")
Observation teams made use of specialized equipment such as duck blinds and isolation suits to avoid early first contact. They sometimes also underwent cosmetic surgery to allow themselves to better "blend in" with the populace they were observing. (TNG: "Who Watches The Watchers", "First Contact"; Star Trek: Insurrection)
The Enderprizians were a society based around Starfleet and the USS Enterprise, caused by their encounter with Ensign David Garrovick when he attempted to covertly save them from a danger without breaking the Prime Directive. An Enderprizian revealed in 2384 that Garrovick, after being saved from death by the Enderprizians, had warned them about the Prime Directive and that they weren't ready for the Federation and its technology, but it had become something to believe in for them despite the Enderprizians being well-aware that they weren't actually a part of Starfleet. (PRO: "All the World's a Stage")
In the 24th century, the Denobulans placed weather modification towers on Halem'no to protect the Halem'nites from deadly dust storms and to give them rain. Although this was done covertly with the towers disguised as mountains so as not to break the Prime Directive, it still resulted in accidental cultural contamination. By the late 32nd century, the Halem'nites believed that their world had been destroyed by gods in retaliation for ancient wars and that the sacrifice of the Mother Compeer had caused the gods to give them rain again. Due to the High Summit failing, the Halem'nites began sacrificing to these gods in order to get the rain back. After repairing the High Summit, Captain Michael Burnham of the USS Discovery decided to break the Prime Directive and inform the locals of the truth in order to get them to stop the sacrifices. Burnham suggested to Ohvahz that the Halem'nite gods could still exist, they just now knew that other races did too. (DIS: "Whistlespeak")
The philosophy behind avoiding cultural contamination seems to stem from the concept of a cosmic plan as addressed in "Pen Pals". The main concern seems to be maintaining a natural diversity (IDIC) of societies. Another related concern is the introduction of advanced technologies into societies that are considered culturally unable to handle them properly.