iOS has its roots in web apps. The original iPhone didn't support third party apps, and Apple was pushing developers to use web technology to make apps. This at

iOS has its roots in web apps. The original iPhone didn't support third party apps, and Apple was pushing developers to use web technology to make apps. This attitude persisted for a long time and to an extent persists even today. When they introduced apps, they didn't want web apps to run differently in, say, the embedded browser of an RSS reader, than in Safari, because users have no clue that there's such a thing as different rendering engines and would be confused. Of course, for a long time, WebViews and Safari used different versions of webkit, but at least they had identically implemented APIs for integrating with mobile hardware and such.