Guys, not every design decision in D&D was made because of "realism" or logic; some things are the way they are because of thematic considerations. Besides which, you can bypass the "Why metal scimitars but no metal armor for Druids?" question with the introduction of (enchanted) crystal or dragonbone blades.
Meh. I get it. It's also not like I homebrew armor when I play with people. We just accept D&D armor for what it is and move on.
However, I also wouldn't cry if they made armor a bit more interesting and a bit more real than 5e currently has it.
Of course, I always preferred the Damage Reduction armor systems. I thought Damage Reduction made so much more sense. Armor slows you down but the better the armor the more it soaks up damage. So you might get hit more, but the enemy can't get through to injure you. Meanwhile, light armor means your more agile and harder to hit, so you might have a higher defense without armor but one lucky hit takes you out.
In my experience, players always felt more rewarded if they hit more frequently, even if they only slowly dwindled down their enemies because of DR. On the other hand, high DR could get real frustrating and often they would hate their weapons, saying they weren't good enough. The worst was when a DR was beyond a weapon's max damage. It was like, Well, we're screwed. Still, it made more sense.
That armor's too strong for blasters."
