then don't install anything outside of their walled garden but don't force it on everyone just because you don't want it.
I moved away from apple a long time ago as I wanted to use my phone my way. there's many reasons why some apps don't make it into Google play/Apple store, doesn't mean they're bad. ad free you tube apps, streaming apps, terminal apps just to mention a few.
I may not use apple any more but there are plenty of others who do who would like the opportunity to install what they want.
Also apples logic is a little flawed, if I buy a mac I can install what I want, why should a phone or tablet be different.