We've had this conversation before, but Im not sure the game has ever had it implemented. I think we always came to the agreement that its "bad' to reward DPS players for doing their job. But its w/e imo.
From what Im loosely gathering about Dragonflight, theyre trying to pull away some of the responsibilities that the tanks have and put more onto the DPS players. Which Im completely fine with in all fairness. Tanks in SL's Mythic+ have wayyyy too much shit on their plate, Healers not far behind them, and the DPS are free to be clueless dumb fucks that get to rage at the healer or tank when they arent able to put out maximum epeen damage. If I had to pull a random theory out of my ass, I could see the motive for these changes being based off a goal of reducing social toxicity.