R. Star wrote:
It's conceivable that with the drive to see what's up there, and with no major technological setbacks(like say the fall of the Roman Empire in our own history), they could've accomplished the task in 1600 years, which is roughly what a week of Voyager being there would be. That's given a very generous stretch, but there's nothing saying Voyager wasn't there two weeks or even a month really.
I'm not sure that the development over 1600 years is unreasonable. It depends on whom we are seeing at every point someone is looking up at the night sky in the episode. 1600 years ago on Earth, there were only patches of advanced civilization: Mediterranean, across the Middle East to India and China. At least in the Eastern Hemisphere, that was the extent thereof. Moreover, that was subject to spurts and stagnation. Although it was rarer, there were still patches in which hunter gatherer society persisted, although mostly it would be considered tribal. The big problem with the episode is assuming that the planet is a monoculture.