And they also just hit a good chunk of those 800 players with nerfs:

• Sorcs are going to see a huge downturn in AOE damage and single target DPS. The reported numbers by Zorz Sorcs on PTS was down 400 dps or about an 8% nerf in damage. They won't have their snare on Force Storm, so that's going to be reducing the DPS potential in PVP.
• Madness Assassins just saw their range reduced to 10 meters meaning they cannot kite Marauders as easily. It'll be harder to Death field in target rich environments. Their life steal was reduced from 25% to 10% for Creeping Terror/Lightning Charge Discharge. Leaching Strike saw its damage drop by 20%, which means the health gain faltered as well. This was a pretty big hit to their survivability/playstyle.

Another thing to remember with those numbers is that each of those specs each have more than a single role. All Marauders can do is damage, after all. It lacks... utility, which is what the devs specifically say that they are going to look into.

Each of the Disciplines is presently performing at our desired DPS markers, and we plan to focus on Utility in the future. Specifically, mobility and self-healing improvements are currently being tested. We’ll keep you up to date on changes in the coming weeks.

There aren't enough utilities that change how Marauders play, while classes like Sorc get the option of Bubble Stun, Healing Bubbles, 25% reduction to damage after stunning, Force Speed to break/grant immunity vs movement effects, AOE Bind on Overload, Force Speed after Barrier refresh/longer force speed, healing during Force Barrier, and so forth. When I fight a Marauder, I don't have to really be concerned about the effect of his utilities once I know what spec he is in.