Jony Ive: "We're making it so simple that we're hiding the navigation controls so that only those in the know or who accidentally stumble on it can show the bar again."
I agree that there was no reason to not include an option to keep the bar persistent (and the default should be what the majority wants), but Chrome has been doing this on Android for years with no option to disable it, and since I use an Android phone, it's very annoying, especially when I'm reading an article, just want to look something up, and have to swipe and lose my scroll place just to open a new tab.
Reading on the iPad now, every time I want to look something up or flip tabs or navigate back and forth or save a book mark, I have to swipe the screen; it's just an extra annoying unnecessary step every single time.