>iOS is extremely closed, where as Android is relatively, indeed, if you fork the code, extremely open.
That's true enough. However, what one can actually do with the device isn't just limited by the OS or available software, it is also limited by the range of available accessories and hardware - which is influenced by historic market share and hardware consistency. In some areas, one can 'do more' with an iOS device because it has better support for (and is better supported by) 3rd party peripherals, such as docks, headphones, condenser microphones, electric guitar cables, camera remote controls etc.
For example, the 'freedom' of Android device makers to go their own way on things like the implementation of wired headsets (using different mic voltages to each other etc) means that there just isn't the choice of headsets with the functionality offered to iOS owners.