Most people hate doing old content. I am always lagging behind on end game so I always have a hard time catching up, because its almost impossible finding people to run the older stuff. Everyone wants to be carried to the latest progression content.
I will also add that most people want the easiest and most efficient route to best gear because they don't have time to wipe for months on any content. The slight buffs echo will provide will help healers and DPS checks. People still have to dodge stuff properly.