I'll admit now, I havent, yet read everyone's opinions, so I apologise in advance if I'm repeating someone.
I think a solution that finds a happy medium in the armor issue is one that is both somewhat realistic and also used by the PnP system Anima.
The you work it is that different armor types provide bonuses against different damage types, call it DR or AC or whatnot.
For example, Full Plate Armor will provide a great defense against piercing and slashing attacks, but bludgeoning attacks still break through and elemental attacks really suck (don't want to get electrocuted, cooked, or frostbitten in there). Leather Armor, on the other hand, has okay protection against most of the physical damage types, but it provides great resistance to lightning. Fur Armor will do great against Cold. Chain Mail is great against slashing and bludgeoning but not so good against piercing.
This is somewhat realistic because armor evolved throughout history as a response to the popular weapons used. And of course the weapons used changed as armors did.
Anima goes one step further by providing a Use Armor skill value that can be increased to allow players to layer soft armors with hard armors to create hybrid defenses (Plate Armor over Fur Armor gives good physical defense while still keeping the wearer protected from cold attacks).
If you want to go that far, that's up to you, but I think that having different armors be good against different damage types, the squishies may still want to wear heavy armor if they are getting ready to take the front lines in a war.