Well, this is exactly it. iOS should have redundant security policies that don't take fallible App Store reviews for granted anyways. Apple didn't really account for this, presumably to hedge the validity of a single App Store. Now they're acting like the victim when they gave up proactive solutions to chase more money. I can't empathize with that logic, even if they drag users into the regulatory bear trap with them.
Apple has every opportunity to make things right. Sideloading works fine on Android (or, Mac); getting it "right" is eminently an implementation problem. It would be incredibly sad for Apple to fight down this legislation through bad faith compliance and self-sabotage. Not unexpected or poor entertainment, but very sad and unnecessary.