How World Quests Are: Here is about 20 Quests specifically designed for this in each zone. Have fun doing them for the rest of existence.
How they should be: Here is about 20 Quests specifically designed for this in each zone PLUS each zones original questline. Have fun.
Pandas: Here is 10 Quests, go do them and you get 2k Rep and 500g guaranteed.
Legion: Here is 20 Quests, go do them and you get 2k Rep, maybe some gold, and a really shitty piece of gear that a fresh 110 will never touch.
How were the Pandaria ones not more rewarding again? Having a really awful/low chance to get things doesn't make them better. I would rather be getting guaranteed trash with good stuff at the end of a grind than be RNG'd out of getting trash and the good stuff. I believe the words here are Item Security.