That's kind of a common misconception about DBM.

You need to learn boss mechanics and what to do, because Blizzard designed the fights with DBM in mind. That's why almost every WOW fight requires player movement, smart use of interrupts and CDs, situational awareness, and knowing when and how to change targets.

DBM is not going to move your character out of a fire or interrupt a boss spell for you. The people who simply try to be top DPS without paying attention to anything rarely make top DPS because they die early, or they never get past the first one or two boss fights in a raid.

Trust me when I say that DBM didn't make things easier. I played WOW for 5 years at the bleeding edge of raiding, both as a primary tank and as the class lead/top 5 DPS in the guild.