They are actually nerfing skills/traits depending on the elite specialization in use. What a terrible "solution". They already did more or less the same for Harbinger instead of just adding a cooldown (of 3 seconds).
Dhuumfire: Reduced burning duration from 3 seconds to 2 seconds when the scourge elite specialization is equipped in PvE only.
And Scourge gets nerfed hard again (Harbinger only slightly). After it was nerfed to the ground in June, then brought back again, then buffed even more (with the expansion), ... and this current nerf will most likely be followed up by a significant buff again. This is getting silly.
Those changes range from 30% to over 60%. WTF!
It's PvE. It's not competitive. Let people have some fun. And when you really feel the need to adjust something, don't use a Sledgehammer.