> There's nothing inherent about usability that requires jailed computing.
Not a requirement, but there is a correlation. Programming for an unjailed ecosystem takes more effort to support the vastly wider environments on the devices. Classic example (in an industry largely orthogonal to Apple, to factor Apple out of the discussion): game programming for a PC versus a console. The PC game company has to support a million different combinations of video and sound and input hardware and operating system, which takes mountains of effort (or cost) that the console company can put into the actual game experience instead (or save the costs.)
This happens at smaller scales too. An iPhone developer has to support exactly one form factor, exactly one screen size, exactly one input method. An Android developer needs to contend with a wide range of screen sizes and resolutions and keyboards and touch responsitivity. Sure, it's possible for the Android developer to accommodate all those devices. But we live in the reality of the capitalist market, where the resources to make that investment of time and effort may not be available.
Taking choice away from the user, imposing a jailed environment, can indeed lead to a better experience overall, in that the content producers can focus more tightly.
Yes, this was always the argument given in support of the monopoly Microsoft Windows used to have on commodity computer operating systems. Some proposed that having only one platform choice was more economically efficient for the industry as a whole. I don't think Apple was really on board with this idea back then.
I do not think that requiring all computers have only one display resolution for the convenience of software developers ends up being a winning strategy in the long run. It may be a winning strategy for Apple's business of course, at least until Apple decides to do an iPad or a "retina display" or for whatever other reason decides that a different form factor is in their own interest.
Not a requirement, but there is a correlation. Programming for an unjailed ecosystem takes more effort to support the vastly wider environments on the devices. Classic example (in an industry largely orthogonal to Apple, to factor Apple out of the discussion): game programming for a PC versus a console. The PC game company has to support a million different combinations of video and sound and input hardware and operating system, which takes mountains of effort (or cost) that the console company can put into the actual game experience instead (or save the costs.)
This happens at smaller scales too. An iPhone developer has to support exactly one form factor, exactly one screen size, exactly one input method. An Android developer needs to contend with a wide range of screen sizes and resolutions and keyboards and touch responsitivity. Sure, it's possible for the Android developer to accommodate all those devices. But we live in the reality of the capitalist market, where the resources to make that investment of time and effort may not be available.
Taking choice away from the user, imposing a jailed environment, can indeed lead to a better experience overall, in that the content producers can focus more tightly.