I dont run old content often, but when I do.... I enjoy seeing people do it for the first time. Just lets you know that new people are still flowing into the game. As a tank you have an option to partially allow people to have the best gameplay experience and so letting people do simply things like watch the cutscenes or grab treasure chests out of the way help.

I wish those old instances gave better rewards for endgame players. It would probably encourage me to run those again.