I agree with this. Even at higher levels, heavy armor should protect more than light armor, otherwise, what's the point? We need balance. Each type of armor should have its ups and downs. Heavy armor protects more, but slows you down, whereas Light armor doesn't protect you nearly as much as heavy armor would, but lets you move much quicker, allowing you to escape enemy attacks instead of just taking them and absorbing the damage.
What you been smokin'? This is TES, as I've repeatedly been told by Bethesda apologists for some time now. They don't do balance. They don't bother with sensible gear or itemization models- it's all generic and blended together. They don't make hard levels or any challenging stuff for higher-level players. They've always let players get overpowered quickly and easily with no thought or care for how that sloppiness can ruin the gameplay for many. But, since they have never bothered to do any of these things (or a lot of other things that would make TES infinitely better), we should never expect any of those things, or ding them for not trying harder to do them right. They just make big, pretty, soulless gameworlds where you gotta gimp yourself and depend largely on your own imagination to make it interesting, because the normal RPG/action framework that people are used to from more complex and well-built games, is largely missing here.
But, it is a pretty game.