You care very strongly about the walled garden so much so that you’ll ignore thousands of other compromises compared to other devices that you may not like. That’s rare, but you’re on Hacker News so of course you aren’t like normal people when choosing a phone. You can’t assume most people will do what you do when they haven’t even heard of the walled garden issue so it literally could not be on their list of considerations.
I’m guessing I could say you don’t care about privacy or usability or something else based on your phone choice. But you’d say no I care about not having a wallet garden and thats why I chose it. Well in the same way most people didn’t choose to have a walled garden. They went to the store and bought one of the most popular phones and regardless of brand all their apps came from an App Store so they didn't even know the difference when they were deciding between other compromises like price, availability, network, battery life, ease of use, etc.
In fact, most these people never had an App Store before their iPhone so it seemed like an extra thing no one else had instead of a locked down Apple monopoly. Hindsight is 20/20.
None of these people would be upset if you put in a power user setting to allow third party apps. They wouldn’t even know it was there. So don’t say they “chose” that they didn’t want it. You can’t say people chose to ban something they don’t even know exists.