You're all right obviously, but as far as I know, DHs have little in the way non-sheet damage mitigation, don't they? Like, even less so than wizards it seems.
As Addnan said, aren't DHs just supposed to avoid getting hit?
Let's see their potential options for DH defense.
Exclusive skills (not including stuff like Unity and Legendary gems):
Evasive Fire - Hardened (used as additional source of defense)
Vault (disjoint skill)
Smoke Screen (disjoint skill, temporary invulnerability)
Awareness (cheat death passive)
Fan of Knives - Bladed armor (more armor option, might see play in that Shadow's Mantle set in 2.4)
Shadow Power (life on hit passive + 35% damage mitigation. Doesn't see play because people want other talents plus the 35% doesn't compare to something like Epiphany Desert Shroud's 50% mitigation)
Boar Companion (gives you more resistances but no one uses this over the Wolf companion for the really high DPS)
Elemental Arrow - Nether Tentacles (just another form of life steal mechanic. Doesn't actually provide damage mitigation)
Sentry - Guardian Turret (AOE damage mitigation of 15%. Conditional damage mitigation and people would much rather use any other Sentry option for a M6 build)
Vengeance - Seeth (another life steal/life on hit mechanic... Vengeance in general gives no damage mitigation option)
Passives:
Perfectionist (used to be much better than it is now. Still sees play. 10%+ all res and armor)
Leech (more life on hit)
So really only the new Bracers and Shadow Power provide any usable raw damage mitigation. They have some ways to gain more life on hit and some more armor/resistances but they don't have enough mechanics to prevent one shots. What they probably need is some passive/skill to give them some dodge bonuses back and some additional damage mitigation sources.
There aren't even that many Legendary items that mitigate damage for Demon Hunters. Now compare the defensive options compared to Monk:
Inner Sanctuary all runes (straight up 50% DR. Used in support build and the generator build)
All Mantra Salvation runes (straight up additional resistance gain plus additional bonuses)
All Mantra of Healing runes (straight up healing passive with a defensive shield option plus some very powerful runes in it)
Epiphany - Desert Shroud (straight up 50% damage reduction)
Dashing Strike - Blinding Speed (insane dodge bonus)
Blinding Flash (increases the enemies chance to miss which is like gaining a multiplier dodge bonus)
Tempest Rush - Bluster (decreases incoming damage of enemies)
Breath of Heaven (a straight up burst heal for you and your allies)
Crippling Wave - Concussion (decreases incoming damage of enemies)
Cyclone Strike - Healing Wave (another healing option but this one sucks because there are other better rune options)
Serenity All runes (temporary invulnerability)
Seven Sided Strike - (offensive skill that gives your temporary invulnerability)
Mystic Ally - Enduring Ally and Earth Ally (more defensive options in terms of healing and increased maximum HP)
Mantra of Conviction - Submission (decrease incoming damage of enemies)
Passives:
Guardian's Path (dodge bonus)
Resolve (reduces incoming damage of enemies)
6th Sense (all non physical DR 25%)
Harmony (basically a huge toughness increase because of flexibility in items and additional AR source)
Near Death experience (cheat death passive)
Beacon of Ytar (IMO this is both an offensive and defensive skill. A lot of defensive skills are CDR based so having Beacon of Ytar actually greatly increases your defensive potential)
As you can see... Monk has a more diverse range of defensive options of DH which range from healing, dodging, damage reduction, reduction of incoming damage and straight up damage reduction.
One thing I would like to add is that Demon Hunters actually have a couple of defensive Legendary items... the problem is that they are a bit unreliable AND they are in the Chest armor slot (ie. Cloaks).
Cloak of Deception and Beckon Sail.