Any device too specialized to run the full Internet suite can be assumed to be too specialized to be treated as a fully general platform for unknown applications.
That is from David Clark et. al, Addressing Reality: An Architectural Response to Real-World Demands on the Evolving Internet, and yes, it is italicized in the original. They meant for it to jump out. Those twenty-eight words are the clearest and most succinct link I have seen between the power of the general-purpose Internet and the power of the general-purpose computer. I am not sure the statement is entirely correct, but it would explain a lot. The application of this assertion to the cell-phone ecosystem, with special attention to the iPhone, is left as an exercise for the reader. And query whether the converse is true.