ehh...what? I think ya need to recheck some things, it′s quite well know it was the invention of the black powder gun that basicly single handedly spelt the end of the heavy armour knight just because the fact such a rifle could shoot threw a metal armour with ease, and when 20 peasants could suddenly lay down that kind of fire it became clear a charging row of knights where sitting ducks.
I still say in a setting where bows are still justified, guns can too, espcially if you think outside the box and think of ways magic could help guns, rather then the two compete.
TES is a different world, and the rifle wasn't invented first.
Even so, people wearing Heavy Armor IRL didn't have a "Restoration" option. And all fights would be simplified down into "load, shoot, dead" no matter what, which would make the game boring. If you add it so that they can't kill anything in one hit, then what's the point of them since you can't make a gun do more damage than it already does? You couldn't advance in "Gun" skills.
Lore is against it anyway, that's my main reason. I'd love to play a fantasy game like TES with guns, but it doesn't make sense in TES. You're attacking everybody who mentions anything that you don't like. Which is funny because many of the people who want guns also "need" to try to force their views, I honestly think somebody's just looking for a power trip. If we didn't see windmills in Oblivion, and the most advanced thing was a gear that opens up a gate in Kvatch, how do you expect them to suddenly have an "Aha!" moment and make guns if their main research goes into magic and alchemy within 200 years?
They don't advance in technology in TES, they advance in Magic.
Again, I'd be fine with flintlocks and rifles if there was a logical reason to have them. But so far there really isn't since nobody really needs them.