Damage from Death From Above should not be any different in this patch. All that was adjusted was the radius of the effect. Damage is applied faster now (every .5 second instead of every second) but the overall damage is the same.
If you believe this should be the case, then I suggest you look into the numbers. DFA has very clearly been reduced in the damage it deals. Forgetting the radius nerf, people stood in it, now dont really have to move as the damage isnt really a big threat to them. however, if they do decide to move out, its a very very short walk to do so.
This was a great ability with a reasonable cooldown that could be used to put a lot of pressure on healers trying their best to keep people up, or themselves when clustered around a perceived safe zone (pillars in Voidstar for eg).
Now, it seems like that it only manages hits of 400-600 per tick, and NOT at an increased tick rate as someone suggested before.
Look at this ability, and get it fixed.