Making Inner Beast off-gcd wouldnt be game breaking and would not make WAR's DPS King of the hill. Espcially when you consider:
1. WAR comes in Dead last in having Off-GCD attacks (Next to WHM). As it is in game today, Warrior has only 1 exclusive Off GCD attack, Brutal Swing with a depressing 50 potency. Sure we have Mercy Stroke with a 200 potency, But thats very situational & is shared with PLD, MNK, DRG. At least PLD has Spirit Within (300 Potency) & Circle of Scorn (100 Potency +30 potency DoT), Both of these can be used every 25-30sec with no limitation of needed wrath stacks + they can use Mercy Stroke too.
2. To even get stacks to use Inner beast, you have to be in Defiance in the first place. This factor alone destroys any hope Warriors had of being a great DPS Tank or even coming close to a True DPS, DPS. Its laughable to think WARs DPS in defiance will come close to SMN with Festers, DRG with Jumps, MNKs with Grease Lightning, and BLM with astral fire Flares. You focus on the potency but you forgot to account for alot of other things like Gear, Job Stats & Traits, and how many off GCD attacks other classes have compared to WAR. When it comes to DPS, WAR dps is near the bottom of the list.
3. And lastly Mathimatically you might be able to use Inner Beast every 20 secs, but we all know that is not the case in real life, especially in boss fights. Sure, you can spam it and your dps will go up, but you will be hurting yourself in the long run when you really need it for the mitigation. And then what will you say ? "I'm Dead, but at least i hit him really hard.... No, Your primary focus isstaying alive, not dps, the added dps would just be a bonus. A Smart WAR will not spam Inner Beast unless its for killing trash. A Smart WAR will save it for right before a big boss hit. Secondly, A 20sec Inner beast is only possible in a fight that requires no movements and no debuffs (slow, paralyze, etc) which are becoming less and less as SE becomes more and more creative with Boss fight Dynamics. And if you are able to pull off 20 Sec Inner Beasts every single time while dodging fight dynamics, Then Good job, 20sec Inner Beast is a fitting reward for your great play.
Your response Sounds like a knee jerk response,which is strickly your opinion. Everyone is entitled to their opinion but I dont think anyone likes your idea and doesnt want to see Inner Beast Nerfed to 150 Potency. It is our signature move and should be strong.