Offense does not equate to 'fighting'. In many cases, an offense form will deal damage, but can't take it. This is not particularly helpful when fighting a mob with as many hit points as a cabal guardian.

If you play a variety of warriors, you'll probably discover that a number of them (especially pre-second-spec) aren't set up to retrieve solo much better than you are, and they need at least a starter set of gear to do it.