As an 'end user' I guess you're rarely aware of the downside of apple's restrictions. Overall I do agree with them, but sometimes they do work as a bit of a roadblock.
An example from my own work: I write camera apps. Apple give us *very* limited access to the camera, and we can't do a lot of basic stuff as a result. Simple things like setting the exposure and ISO on the camera - this would be incredibly useful, and would mean we can write *much* better camera apps. But those apps can't be made, so they don't exist and you don't know what you're missing. 🙁
Well, actually I DID make an app with manual exposure control, and the improvements over the native camera app in low light are pretty spectacular. But I had to use a workaround to do this, and it's extremely limited. I could do so much more with direct access.