When I was young, Star Trek was not only my gateway to science fiction - aside from a few books like Ender's Game or Escape from Splatterbang, it was essentially coterminous with the entire idea of science fiction. In Central Ontario in the early 1990s, before the ubiquity of the internet and the cultural universalization of what had once been the domain of the strange and timid nerd, it was easy to fall into that pattern; when it came to televised science fiction, Star Trek was pretty much the only game in town--resulting in an audience concentration that enabled things such as CityTV booking out the SkyDome in 1994 to screen the last episode of Star Trek: The Next Generation. That wouldn't necessarily happen today; after eighteen years, the fans have diffused.
Honestly, it's for the best. In many respects, Star Trek can be seen as "beginner's science fiction," an easily approachable, entry-level gateway to everything that lies beyond. A similar thing happened fifty years ago: when the pilot of the original Star Trek was screened at the 24th World Science Fiction Convention in 1966, science fiction fandom was vastly, vastly smaller and more insular than it is today. After Star Trek hit the airwaves, sf conventions were deluged by new fans who had been introduced to this entire new world of possibilities. At the time, of course, there were concerns that the tide of new fans would swamp the structures that had existed up until then; David Gerrold's The World of Star Trek, written in 1973, gives a good look into the concerns of the time. Still, it didn't end up becoming a dry run of Usenet's Endless September; many of the new fans integrated themselves into the existing structure, and Star Trek provided another avenue for people to become aware of this thing called "science fiction."
They may move on, but on the whole Star Trek itself remains behind. When I finally started branching out into things that weren't based on an idea by Gene Roddenberry, it was like the gates of the world had swung open. At its core, Star Trek is fundamentally limited by fifty years of precedent--a dense kudzu of stories that often contradict each other, and restrict possibilities.
Honestly, looking back on it now, at times Star Trek just seems fundamentally uncreative. I know that this is mostly a result of how television has changed in the last twenty-five years; after its debut in 1987, almost every episode of The Next Generation was effectively self-contained, and when there was a two-parter with the "Previously on Star Trek: The Next Generation" trailer, you knew you were in for something out of the ordinary. Being unable to build on what you've built previously, except for minor callbacks like Picard's Ressikan flute that don't require any prior familiarity anyway, means that everything has to be simple.
For me, what really sums up this sort of attitude is, for me, the way it deals with planets. Only a handful of worlds in Star Trek actually have their own names, and even then they're almost always derived from the people that live there--Vulcans come from Vulcan, Cardassians come from Cardassia, Ferengi come from Ferenginar, humans come from Huma, and so forth. Klingons come from Qo'noS, which is the only departure from the pattern I can think of. Otherwise, the tactic is always "Star Name, Orbital Position." So humans would instead come from Sol III, and so on. It doesn't matter whether it's a colony just starting out or the sprawling homeworld of a species that numbers in the billions. It strikes me as a sort of creative sterility. After all, by the time of The Next Generation the writers had almost moved away from the senseless Greek letter combinations that were in vogue in the 1960s, aside from insipidities like the "Alpha Omicron system." They still had to come up with the name of the star anyway--why not just apply it to the planet of interest, instead?
It's certainly more natural. In fact, as I got older that was one of the factors that attracted me to Star Wars: the fact that all the planets had their own names! Like they were important in and of themselves, that people lived there that weren't satisfied with living on the Eastern Continent of Beta Whatsis IV! This was particularly true in the Expanded Universe novels, which I got into through the Thrawn trilogy--a trilogy written by Timothy Zahn, someone who'd already found success in science fiction writing, and who brought those sensibilities to the Star Wars universe.
Honestly, after fifty years that sort of thing is what Star Trek is in dire need of: a re-evaluation, a re-opening, more possibilities for creativity to flow in unanticipated directions.