Because it's Apple's problem regardless. The iPhone is at-odds with it's identity of security and privacy even without the threat of sideloading. The App Store,

Because it's Apple's problem regardless. The iPhone is at-odds with it's identity of security and privacy even without the threat of sideloading. The App Store, a supposedly curated and well-reviewed platform, is dominated by pay-to-play games and ad-supported datamining apps. First-party Apple software like iMessage is perpetually vulnerable to escalation attacks due to the way it's designed. iCloud is basically a fancy sticker on state-owned and surveilled datacenters that Apple markets for an easy buck. Now, they want to argue that sideloading is the straw that breaks the camel's back? Not Safari, which has enabled lord knows how many scams and privilege escalation attacks. Not the App Store, which disseminates exploitative and fraudulent content under the guise of simplicity and security. Not iMessage, the perennial attack-vector for escalated malware. Somehow it's the sideloaders who are the problem, for daring to suggest that the iPhone should rely on OS-level security rather than arbitrary (and often wrong) first-party curation. Who do you suggest we blame?