- That's not 100%, no matter how you put it. You can get in an unlucky streak and not crit for 4-5 attacks and be left with half your Fury capacity (and even smaller chance to not crit - and I'm not even mentioning the chance to return Fury yet).
- Unless you use Overpower and Revenge with increased crit chance (and for added AoE dmg). Check the 4th point then about skillset limitation.
Extremely small AoE
- It's very rare to be able to hit multiple elites, and absolutely impossible if they have big hitboxes (Tremors, Hulking Phasebeasts, etc.). Dealing with Trash mobs takes quite some time with just HotA. You'd need to have another spender/AoE like Seismic Slam. Or an AoE generator (and miss out on the dmg bonus from Frenzy/Bash runes).
The Fury return isn't guaranteed (Smash doesn't have a 1.0 proc ratio)
- Good luck with the build without a generator at all. Let me know how that goes when you're out of Fury.
The build requires a specific skillset
- Namely those that improve your crit chance/crit dmg (2 passives), and then Battle Rage with Into the Fray, and then you can't really use WotB with infinite duration, You may be able to add War Cry in there, and then Overpower and Revenge for added crit/AoE.
But you're still left with a build that has almost 0 dmg mitigation (only 1 passive, no Ignore Pain), 0 mobility (no Sprint or Leap), almost no team utility (except for the mandatory War Cry, no stun/taunt/Threatening-Shout/Ancient-Spear).
They could reduce the AoE of Smash even further (make it 100% single target) OR reduce the proc ratio, that should prevent people from spamming 50 HotA in a row (which I presume is what you want).
I think you're just jealous of a fellow Barbarian critting for 1.5 mil with every attack while you can't do jack with your crappy DH.