Why the hell are some heavy armor types included in this? Some of the coolest looking heavy armor are upgraded by that perk, and it's stuck on the light armor side. If you're using heavy armor, why would you want to waste two perk points in the light armor half? Why couldn't Bethesda just have split it up into two different perks, one on the light side for light armor and oine of the heavy side for heavy armor?

Use "smithing perks overhaul", it's a great mod that actually makes sense.

I think it has to do with an over abundance of Heavy Armor types, just to balance it a little.

Heavy armor is kind of higher grade light armor?

Less developed heavy being able to be up graded?

Seems a kind of logic there.

In the other hand on the heavy armor side are the best weapons in the game. If you are using light armor you still need to waste perks on heavy armor side if you want properly upgrade some good weapons. Everything is up to your own choices. And if this really bothers you then just open the console and add the advanced armor perk to your character in that way. There's really no problem with this.

Smithing is a mess, that's what the problem is. It was poorly thought out, similar to a lot of other things in this game. Really though, the only heavy armor you are missing out on is Steel Plate, which isn't a huge loss. Just use enchants and pots to get it up to the same (or greater) level of gear you already have. Here's hoping they get smithing right next time!