Deception is just as viable as madness in pve. Stop with the misconceptions and discouraging people from playing a well rounded spec that CAN top the dps meters in ops.
The last patch gave Deception a nice boost and people should try the spec for themselves.
Is it viable? Yes. Is it optimal? No. Think like a raid leader for a minute or two. In an 8m group, which the majority of runs are, there's a maximum of 2 spots for melee DPS. 1 will go to a Marauder as they have top damage and Bloodthirst. That leaves you competing for 1 slot against all other DPS classes. Snipers, PTs, Marauders, Juggs and Mercs all pull equal or better DPS. Snipers and Mercs are safer due to range. 2 Marauders means 2 Predations and Bloodthirsts, which is a very good thing. Juggs and PTs are both more survivable due to heavy armor. Scale it up to a 16m and it doesn't get much better. BT is only party-wide, so that means 2 marauders to get the buff out to all DPS. and a potential of 2 slots to fill with a Sin DPS. This isn;t to say that Sin DPS is bad or useless, just know that you are fighting an uphill battle when it comes to finding a group for Ops.
EDIT: To be fair, Sorc DPS isn't all that highly sought after either. They're noticeably behind similarly geared/skilled Snipers and Mercs. OP, if you're looking to only DPS and do not mind having no role flexibility, I'd recommend rolling a Marauder or Sniper. PT is a good option if you want the ability to tank. Sorc is probably your best option if you want to be able to heal. While their DPS isn't in the best place right now, Merc healing and Operative DPS are worse off.