... i'm not sure if it's bad game design or beth's game philosophy.
The fix is very easy, believe it or not:
Give enemies armor.That's it. Did you know that all creatures in the game who are not playable NPC types have a zero armor rating? Whoops... could have used a little polish there for the bestiary. Also, the NPCs that DO have armor... have low skills -- which, as we have seen in this thread, makes all the difference. What's the point in giving a high-level bandit chief steel or better armor if his skill is only 20? Might as well be naked... especially fighting the player who has intelligently armed and armored himself within the ruleset that nobody else seems to know about in Tamriel.
They just need to adjust the enemies' stats and equipment... and by "they", I mean modders.

Beth ain't gonna do it.
-Loth
PS Imagine taking on a roomful of high-level vampires who are wearing more than necromancer robes, and have very high armor skills. Hell, give the dragons 50-60% damage immunity from their scales which are supposed to be some incredible armor if you wear them. Now the game isn't a breeze anymore.