Labyrinth and Syrcus Tower...

[linay]

Efficiency. There's a minimum and a maximum priciple.

Minimum priciple: Get a fixed reward with as little effort aus possible.
Maximum prnciple: Use a fixed amount of effort to gain a reward that's a big as possible.

Since the reward in roulettes is fixed and the effort is variable, the only reasonable thing to do is minimizing your effort to get the fixed reward.

Now if all Raids took the same amount of time, but the rewards varied, people would jump on the one that grants the biggest reward for the fixed effort.

Meh, there's efficiency and then there's limiting yourself to running the same thing daily in a video game.

But hey, as long as people show that they don't mind doing that, I guess that's one more evidence against all the people that complain that this game is the same thing expansion after expansion or that it's too easy. That's what people want and the developers don't mind being efficient themselves in how they release content.