An issue with melee is that it goes completely unpunished defence-wise as you can simply wear robes/leather while fighting magic based enemys/bosses. You fight at the same DPS output (minus boot strength) in full robes vs a full melee set currently.
I propose there to be an actual tactical tradeoff to wanting to gear for magic resist by adding a slight melee accuracy nerf while using robes (and potentially leather). This way the melee player will need to decide between optimal dps or optimal defence. This will also make being a mage a more appealing option without actually buffing mage itself as they will have something they specialize in.
If you want a lore reason: it's hard to swing a sword with big floppy robes getting in the way.