To GM a game, you need to be able to improvise details, and for me, that means that the game setting has to make sense. I can't just say "here's a ruined tower filled with skeletons." That doesn't work for me. I have to know what the tower's original purpose was, why it came to ruin, and how the skeletons got there. If I don't have that logically coherent framework to build on, the details I come up with don't hang together and everything falls to pieces.
So to run something like Star Wars, before we even started I had to make sense out of the setting's technology. There are two big weird things about technology in Star Wars: first, it's very static. KOTOR (the X-Box game) and SWTOR (the MMO) are set four thousand years before the movies, and the technology is almost exactly the same. Technological change in Star Wars must be very, very slow. And second, if you subtract off the obviously futuristic elements like blasters and FTL travel, it looks a lot like real-world technology from the '70s.
Now, the obvious real-world reason for this set-up is that everything is trying to be consistent with a movie that came out in the '70s in order to satisfy the audience's desire to experience more of that setting, and that original setting was constructed as an overlay on real-world technology in order to be relatable. But it's fun to come up with an in-universe explanation for why that is the case.
Adding on the technological overlays is easy. Subtracting off the real-world changes over the last 40 years is trickier. The biggest one is, of course, the rise of personal computing and the internet. The Star Wars setting (as of a month before Ep. VII) clearly has nothing even remotely like modern laptops, smartphones, or the web. How could that be?
The explanation I came up with is: general-purpose computing doesn't exist in the Star Wars setting. Essentially, there is no software, there is only hardware. We see big, mainframe-type control systems, like the tractor beam controls on the Death Star. We also see small, embedded systems in handheld devices, like the rangefinder in Luke's electrobinoculars. These are things that make sense as single-purpose, hard-wired designs.
But a generic device that can be programmed to perform any kind of information-processing task: these don't seem to exist in Star Wars. If every data processor requires electronics that must be designed by hand for that specific task, that will provide a huge brake on technological progress. Add in the need to accommodate the vast diversity of the setting and I think you have the outline of a decent excuse for why technology advances slowly, if at all.
...And then there are droids, about which more next time.