They might be paid, but they are paid the same for good design and bad design. All design is just design, by blizzard management, and so long as they are being “productive” they get a paycheck. Their paycheck is not determinant on whether or not their “productivity” is actually good design, or just mediocre poor design. And that is the reason that triple AAA game companies tend to have worse and worse design as they age compared to indie companies. If an indie company makes a bad game, the company goes bankrupt and the devs lose their job. If a triple AAA company makes a bad design choice in a large game like wow, the devs don’t lose their paycheck at all. It is mediocrity. And it shows.
Addressing this is not something that management is capable of doing, because rating the design choices in a game is what consumers do when they choose to keep paying the sub.
The dev tipping idea is about making the devs strive for better, and to be better. This is the ultimate form of feedback. Its an incentive that would make them be better devs.