It has already been stated.
Mystic Vision is happening more frequently, for slightly less rewards each time, but slightly more rewards overall. I think that your frustration may be misplaced.
You are right: money is all they care about. otherwise the game would just go away. The development teams like that they produce a fun game, but c’mon… no one is here under the suspicion that this is actually a free game.
You spend time, you spend money… in the end it’s all the same, just a matter of degree.
But don’t confuse your frustration with facts.
EDIT: Developer statement: