Three places where a rogue will always fall short.
1. Taunt. Your group requirements are quite rigid because you have to rely on others to be able to drop threat in case you can not hold it.
2. Threat generation. You have no modifier for increased threat or abilities which cause increased threat. Threat is based on damage only.
3. Effective health. You don't have the same level of passive damage mitigation as a conventional tank. You also don't have the same stamina or health modifiers. Armor is always going to be substantially lower and even if you are crit immune, the hits will be larger regardless.
It's a fun area to explore but you will always have these limitations working against you. Those areas will always be in favor of the conventional tanks.
"In anything, if you want to go from just a beginner to a pro, you need a montage." /w TankSpot WTB Montage for Raiders.