It is very difficult for a person living in our own modern world to imagine technology remaining at a standstill for any length of time. I mean, look at the change in our culture in the last 100 years—hell, in the last TEN years even. Its really incredible when you stop to think about it, and to me at least it seems 'normal' that within my generation technology will just keep progressing at the same rate.
Not so the Star Wars universe. My first introduction to the 'Ancient History' of the Star Wars universe was the 'Tales of the Jedi' comic book series (set 4,000 years prior to Star Wars). The art style in these books seemed to show a more 'raw' and 'barbaric' look to everything, and yet the technology presented really wasn't much different than what we'd seen in the movies. The Knights of the Old Republic series (also set about 4,000 years prior to Star Wars) again seemed to show that things were indeed pretty much the same. Lightsabers, Blasters, Starships, all of it. They maybe hinted that less of the Galaxy was explored at the time (Kashyyyk was only just being 'developed'), but for the most part, it was all status quo.
On one hand, this kind of offends my modern sensibilities, but on the other, I've tried to rationalize it away. If you look at the length of Human civilization on our own planet, you will see that there have been times when technology has hit a plateau, and remained basically the same for very long periods of time. I mean, a sword is a sword, right? Horse-drawn wagons are horse-drawn wagons. Sailing ships are sailing ships. From the time of ancient Egypt even into the middle-ages (a span of thousands of years) there were advances to be sure, but everyday life for the average person couldn't have been too much different. So I guess its kind of the same for the Star Wars universe. There have been refinements and minor changes throughout the history of the Galaxy, but for at least 4,000 years there has been a plateau.
Sound rational to you? Well...I'll keep trying to convince myself. In any case, if technology DID advance even half as fast in the Star Wars universe as in our own world, I'm sure all life in the Star Wars galaxy would have evolved into pure energy by the time of the movies—and where is the fun in that?