Over the course of the whole Star Trek franchise, with the various shows and movies, a common fan complaint is that "_____ ruined Star Trek" ( ____ being JJ Abrams, or Rick Berman, or UPN, or a series like Enterprise, which spoiled the canon). And what they mean by ruined is "not staying true to the origianl vision".
Uh, excuse me? It's not a real adventure. It was a dramatic series. In fact, when Gene Roddenberry pitched the series to NBC, he repeatedly called in "Horatio Hornblower in Space". One would do well to read C.S. Forester's novels to see what Roddenberry was talking about.
Obviously Captain Kirk is based upon the Hornblower character. But there is more to it than that.
Picture a time in the age of sail. It could take years to navigate around the world. Ports of call were truly alien and exotic. Because of the distances involved and the speed of ships, weeks or months could go by between meetings with ships of the mother country, let alone communications and orders from the home fleet. A captain, in this case an English captain, represented his country in a way not known in present day. His ship literally was England, and a captain had an amount of leeway - and responsibility - in action and judgement without precedent in scope and power.
So, you have all sorts of dramatic attractions. Romance, adventure, the seduction and fear of the unknown, and, above all, a lot of opportunity for error in judgement. Things can go Wrong, which is what drama (and comedy) is all about.
Naturally, modifications are made for setting. The ship can't really take weeks or months or years to get from one place to another, or for news to arrive from home. The times and distances have to be just right - both for the tastes of the audience and the boundaries of the show. The time it takes for news and orders to reach the Enterprise from Starfleet Command must be long enough so that Kirk has to, at times, take initiative and think on his feet, rather than merely following orders. (With the potential that he may make the wrong decision or one contrary to Command decisions). On the other hand, it must be short enough so that he will occasionally be ordered into an uncomfortable situation, or for him to potentially get in trouble when he fails to obey orders. This creates dramatic tension.
Which brings us back to error. This is the purpose of the triad - Kirk, Bones, and Spock. To visually, dramatically, play out the internal dialogues we all go through when making a decision. Spock, obviously representing the dispassionate and cerebral characteristic. Bones, the gut instinct, the emotional side. The two getting into arguments, yes, even getting snappy and snarky. Presenting Cat Fights, if you will. Kirk, vacillating between the two, questioning himself, but ultimately making the hard choice. And, at the beginning at least, making the wrong choice.
Human error. Foibles, flaws, judgement calls, prejudice, ignorance. And then adapting, improvising, overcoming. That's what we want to see.
But here's the problem. Part of Roddenberry's vision (in retrospect naive, overly optimistic, and ultimately self-defeating from a dramatic standpoint), is that as civilizations and people grow, they improve. They get nicer, and wiser, and well behaved.
Which means they get boring.
Cant' expect any action from the likes of them, and so we must introduce them to situations where interesting characters (read not quite as advanced - Special Guest Villians) put our protagonists into peril. In other words, drama becomes melodrama. The Perils of Pauline.
Contrived situations, which is, uh oh! a sure sign that a series, or a franchise, has jumped the shark.
But in Star Trek's case, not because they've run out of material (fer jeebus's sake there's a whole frickin galaxy of adventures out there!), but because of self-imposed limitations. "Nice people don't do things like that!"
My take on it, at least.