You know, when I think that it's been 200 years since Oblivion I wonder why the world is still technologically the same in Skyrim as it was in Oblivion. Especially when ancient Dwemer and Ayleid technology seems much more advanced. Are the people of Nyrn afraid of technology?
Main reason? It's a game and a constructed world. The designers built it this way, because they wanted it like that.
Secondary reasons:
1) They have magic and other similar things. This means that some of the needs that pushed invention in our world don't exist there.
2) The world's been in a downturn (civil wars, exploding provinces, etc). Heading into a dark age, etc.
3) Yes, they're afraid of technology - or at least not huge fans of it. The Dwemer loved this "technology" thing. And they're all dead. This makes tech not seem like all that great an idea.