I suspect that at least some of these "flaws" are intentional, and are meant to make programming easier, at the expense of some performance.
For example, three of the poster's points (not allowing device property querying, not allowing the programmer to choose where a kernel runs, and not exposting local memory to the programmer) all make programming easier, though they also disallow some types of performance tuning.
One big potential reason for doing GPGPU on a mobile device is to get better energy efficiency per gigaflop, rather than to get huge overall performance like on a desktop GPGPU. In this context, squeezing out all possible performance may not be as important.
For example, three of the poster's points (not allowing device property querying, not allowing the programmer to choose where a kernel runs, and not exposting local memory to the programmer) all make programming easier, though they also disallow some types of performance tuning.
One big potential reason for doing GPGPU on a mobile device is to get better energy efficiency per gigaflop, rather than to get huge overall performance like on a desktop GPGPU. In this context, squeezing out all possible performance may not be as important.