Dem troops are dropping like flies cap'n.
That's just the unfortunate way things happen. It's not so much money they lose from you as much as it is money they gain from the truly crazy people out there. The only time it changes is when the whales start drying up, or when a significant fraction of people start leaving (which then leads to whales losing interest too, since community, etc) and then you see small bones starting to get thrown in an effort to retain players.
Thing is, I'm speaking as a whale. Sure, there are people worse than me, but I'm pretty sure I'm still in the category. And I'm not convinced that this is the best business model.
They're banking on people sticking around long term and blowing tons of cash on these limited time events, but that's only the best strategy if the people actually stick around.
Whales are known for being impulsive, which means that if they aren't feeling the impulse during a particular event, they'll just do nothing. They're literally throwing away opportunities to receive money, because they're relying on TWO conditions to be true:
1) The machine has to have something the person wants
2) The person has to have the impulse to spend big.
By eliminating this shit banner system, they only need 1 condition to be true: namely, that the person has the impulse. Because everything will always be in the machine.
Furthermore, it softens the disappointment of a failed pull, because you'll know it will still be there later.
To pour salt in the wound, since the banner rates have become public information, people can see the exact odds of getting things, and it's more clear than ever that they intentionally shit on you by filling the machine with easy to get 5* items that nobody gives a shit about. They had some units like that in PAD back in the day when i whaled over there and they eventually removed them because they realized how offensive it was to players.