LoL I know what you mean though. Sometimes huge DPS is so much better than massive armor. Warriors are great but not specialized for incapacitating and quickly ripping apart enemies as rogues are. That is probably the biggest difference between them. Warriors are meant for endurance, not so much damage. They can do really good damage too, but they have to sacrifice a lot of their resilience for that. As they grow in levels, warriors can take on much more power through their weapons. Rogues get a lot of their power from their skills. So gear plays much more of a part later on.
Strangely enough, I have a druid with over 20,000 armor and 10,000 hp. My lock with about 1,000 armor and around 3,000 hp can actually kill more enemies at once. She just kills them so fast they don't get many chances to hit her.