I think people forget that Apple is not making devices for the Hackernews community. They are making devices for people that just want something that works pretty well and has reasonable security - even to the extent of protecting them from themselves. They have other things to do with their time than learn about security vulnerabilities and how to avoid them. They want to just click 'yes' on every popup and expect things to keep working. Because they know that they are not qualified to answer that yes/no popup question. And those people do not care much about lock-in and walled gardens. They are not interested in jailbreaking and sideloading apps. They've never heard of Pebble or have any interest in it.

This is 90% of humanity, including people we all know and love.

Apple serves these people pretty well.