> right of exclusion when it comes to what code can run on that ARM cpu
Yes I like it for the phone. The walled garden has very little malware and has high quality apps. I am never pestered to install crapware or malware and I don't have to be paranoid about it. You can still run your own development software on these machines, and software distributed in controlled channels outside of the store. The controls are reasonably convenient and necessary to keep unwanted software out.
Compare it to Android Play Store or much worse the Galaxy store situation. The grass is much greener in the walled garden.
For the Mac, it's a different story, you can and should be able to run whatever you want on it. But iPhone as a product is a well tended garden (controlled but quite wide and powerful) and I can appreciate that.