Deafening Roar is the morph which allows you to taunt, which you would only want if you're playing the tank role. Only tanks should be using abilities which fear/stun enemies.
It makes no sense to put the damage buff exclusively on the damage dealer morph of the skill, when that only encourages damage dealers to fear enemies. It would make far more sense to source Terrified exclusively from Deafening Roar, as that would encourage you to bring a dedicated tank into your group if you wanted to deal increased damage.
PC/NA — Lone Werewolf, the EP Templar Khajiit Werewolf
Werewolf Should be Allowed to Sneak
Please give us Werewolf
Skill Styles (for customizing our fur color),
Grimoires/Scribing skills (to fill in the holes in our builds), and
Companions (to transform with).