Seems like an odd scapegoat. Apple themselves was promoting the iPhone with gachapon games earlier today, it's not like lootbox titles magically disappeared with good DRM. If anything, overly-strong DRM enforcement reinforces the power that lootbox-style games have over the user. It gives the developer more control over the runtime than the end-user, encouraging developers to extort the user however they can.

Sideloading makes piracy a service problem instead of a freedom one, and Apple knows their service can't compete on an unstacked deck.