To make non-App-store apps annoyingly unusable, so the App store will sell more apps, instead of people downloading in other ways?
Just like Apple cripples the Safari browser and PWA apps.
Long term, maybe Apple wants to be able to remote-forbid apps if Apple is developing their own competing app?
Whilst most developers working at Apple understands this, and don't like it? Maybe the developers even feel happy about people here at HN being disappointed, and think that "now the business people here at Apple notice that this causes disappointment" ?