Remember that dps can be flawed. You can have the highest dps on a boss and still do less over-all damage than the tank, extreme example. If your looking only at dps and nothing else your going to gimp yourself. I know a few people that do massive dps on patchwork and thus end up with massive damage done, but when it comes to bosses where you have to move around and adjust your rotation on the fly they still have massive dps but their damage done hit's the ground.
DPS is only calculated when you are attacking(casting, spell is in the air, dots are on the target), if your running around aimlessly your not contributing to the damage done but it's doesn't affect you dps. In theory(can't play right now to test) you could start a boss pop all your trinkets and cooldowns and get 8,000 dps at the beginning and then sit in the corner the rest of the fight and still have roughly 8,000 dps when all is said and done. You can brag to everyone about your leet dps but the fact would remain that you helped the group almost none.
Affliction Warlocks are good at bosses because when everyone is moving around our dots are still ticking giving us more damage done. On the opposite end our dps during that time is going down because we aren't shadowbolting and what not, while everyone elses dps stops as they aren't fighting. This leads to locks having a lower dps but more damage done, and damage done is what you want to go for.
Basically what I'm saying is that while improving dps is good and you want to hit a certain mark, it's not the only thing you should be thinking about. Dps will change drastically depending on what group your in and what boss your facing, but if you consistently around 30% of the damage done your doing fine.