PVP Issue: No one does physical damage anymore.

[Suntall]

Ret can go down the path of near-pure Holy, with the exception of their AA and CS. Against anything with high avoidance/armor, you go Divine Hammers due to its inability to be avoided, and magic damage.

Its almost always been this way btw - The only spec that has ever done 100% mitigatable-through-armor damage is Fury Warrior for a wee bit. Now, everyone has some portion of damage that can bypass armor.

Note, however, that phys. damage mitigation is actually fairly similar for ALL non-tank classes. DPS plate wearers tend to have ~35-40% protection via armor. Now, lets look at the squishies.

Warlock - The lowest damage mit. of all casters. Only defensive ability outside of talents is Unending Resolve, 40% damage reduction+silence/immune interupt on 10 second duration. Talents can boost them up a bit, but not by much. Demo has a bit extra survivability.

Mage - Passive armor buffs gives Frost/Fire a small mitigation boost vs phys. Fire gets 6% damage reduction, Frost gets free slows. Arcane is the weakest spec when it comes to melees.

Priests - Shadowform grants +10% phys damage reduction, giving them close to leather mitigation. Disc/Holy gets +30% damage reduction from melee, putting them close to plate.

Druids - Boomkins get as much armor as Guardians do. Feral/Resto need to assume bear form, greatly reducing their in-spec effectiveness.

Monks - Get nothing against pure phys damage.

Rogues - Evasion/Riposte.

DHs - Blur.

Shamans/Hunters get nothing that protects them against phys. So, generally, among the DPS specs, most are bout on par with each other against physical damage due to passives or cooldowns. Does it suck that the pure phys damage dealers deal, on average, 30% less damage against most all classes? Yes, but do note that the only way to stop phys damage is to kite, CC, or use avoidance if available to your spec. Most casters can be interupted for 4 seconds out of every 15, and LoSd otherwise.

+1
This basicly is the answer to OP and how the ranged - melee balance is supposed to be.

[Soisoisoi]

Sub rogues - their biggest hitters are shadow damage.

The only Shadow Damage Sub has is Nightblade, their DoT (basically Rupture). It is (was? Can't remember if Hotfix or 7.1.5) also dispellable so... yeah.