Guarantee you though, they see that as advertising. Look, Jinx, you're already at 95 of those 100 shards needed to claim these next 5 rewards. Spend those crystals/money, get those shards to get the shiny rewards. It's 100% the entire point behind it.
lots of purchases are gambling, but this is putting that same type of atmosphere in your face and daring you to not spend to get the next shiny thing.
That's not to say it's going to work and it's clearly turning of lots of people. That is the whole reason for it and the very reason they're unlikely to turn it off. Casino's don't give you a path the elevators that does not take you by the gaming floor or shield you from it in any way. They're trying to reel you in.