Oh really? What exactly is this cap and how does it affect the overall defense of the armor? Because from my understanding, better armor=better armor. If the armor is indeed capped, there is no point in ever upgrading. I might as well run around in a set of Legendary Iron armor if a set of Legendary Orcish armor is capped to the same defense.
For all of you who say, it's irrelevant, it's an rpg, it's all about immersion, or this isn't wow. To all of you, that's your own damn opinion. Personally I'm going to get and wear what has the best "stats", period. As a smith that means I'm going to wear whatever I can craft that provides me with the best defense, I personally do not give a [censored] how it looks. I don't have to look at it in game, as such one would expect the top tier crafted armor to be well... top tier. Dragonborn or not, if deadric armor provides me with the best defensive capabilities. That's what I'm wearing, there is no need for me to even look to the last perk. I understand you can get dragon scales and bones at a very early level. But you can go out and buy high level ore/ingots from smiths at the same low levels. So really when you obtain the materials is quite irrelevant.
Logically speaking, the last level of craftable goods should be the "best" per stats. It makes no sense for the teir before to be better, no matter how you want to justify it. It's re-tar-ded. Also if your other point is, you should choose based on what you like. Aesthetically. You should be able to add accents or customize armor. Maybe you want to wear a set of Iron armor that looks like deadric armor made out of Iron not Ebony, obviously you can't do this although it would be kind of neat. But seriously, level 10 armor and weapons should be stronger than level 9. That's just how it goes.
From the UESP:
Damage reduction is capped at 80%. If you are wearing all four pieces of armor, this occurs at 567 displayed armor rating. If you have 100 skill and all relevant armor perks, this requires a smithed armor rating of about 135. You can increase your smithed armor rating by 1 roughly every 2 points of Smithing with the appropriate perk, or every 4 without. Therefore, at 100 Smithing you will need 85 base armor with the appropriate perk, which is not achievable with Light Armor (though Dragonscale comes close at 82 for the set) and requires at least a Steel Plate set for Heavy Armor. With Fortify Smithing apparel you can boost Smithing even further, which can potentially allow any material for which a Smithing perk exists to reach the cap. At the extreme end, you will need about 126 Smithing to make Steel Armor hit the cap, and about 154 Smithing for an Elven set. Unfortunately, Fur, Hide, Studded, Leather, and Iron armors are not affected by any Smithing perks and so cannot be improved as much.
With the aid of enchanting (fortify smithing) and pre-made enchanting and smithing potions, and of course the appropriate armor perks, you can reach the armor cap with any style or type of armor in the game, even hide and iron armor. All without even using a shield.
And the point of that is because this is intended to be an RPG like every other Elder Scrolls where all armors can reach the same stats, because you're intended to wear what looks the best for you or your character.
Also, that whole "re-tar-ded" thing is "your own damn opinion" as well. It goes both ways, friend. And you can edit armor. It's called the construction set. It will be out in January.