Why should Apple do anything about it? Hosting it in the App Store doesn't make it their app, or the owner of even one line of source code for the game.
This is how all freemium apps work. There are literally thousands of them on the App Store. Ads are the easiest way for the developer to make money they spent months working on before releasing it. Every time an ad runs, they make a few cents from the owner of the ad.
How did it get this way? When the App Store first launched, apps were priced like typical apps you'd find in retail box. $19.99, $39.99, $5.99, etc. Then competitors would jump in with a similar app and price it lower to pull sales away from the app they're competing against. The owner of the original app would then lower their price.
You should be able to see where this went. It became a race to the bottom of who could charge the least and still make it worth their time to write the app in the first place. After a while, users got used to paying virtually nothing for apps. I saw one person complain in an app they purchased that it was too expensive at $1.99. Yes, they seriously said that in the review they left.
That left developers in a situation where users practically expect everything for free. Doesn't matter how much time it took to create the app. They don't care. They just don't want to pay anything for the apps they get. I'd love to hear these same people complain when after a week's work at their job the owner says, "No paychecks for anyone this week. Better luck next time."
So where did that leave developers? The only places they could go. By setting up income streams after you get the app. That's ads, or in-app purchases for crazy amounts of money. Like $100 of real money for 500 gems in a (cough!) free game you're playing.
Want this kind of lunacy to end? Stop expecting everything for free.