Warrior Decimate is too weak

[Ralvenom]

Numbers don't mean much in terms of comparing to each other (we'll all have different attribute points).
What I'd like to compare are the different skills, how are we ever going to choose decimate over fell cleave? it's illogical...

Um...that's simple. Look at the tooltip:

Delivers an attack to all nearby enemies with a potency of 280.

Compare that to our other AoE dmg/threat grabs:
Steel Cyclone:

Delivers an attack with a potency of 200 to all nearby enemies.
Ignores the 35% damage penalty inflicted by Defiance.

Overpower:

Delivers an attack with a potency of 120 to all enemies in a cone before you.

In other words, Decimate does more dmg. So, why not use it? Yes, the magic numbers of Decimate aren't as great. But that's because it's an AoE attack. AoEs always does less dmg to each mob they hit than single targets attacks do, but AoEs do either equal or more dmg overall.