probably the same reason why they can not simply remove dingoo OS and replace with dingux
actually that's because no-ones written a driver to use the internal storage yet, and it's a bad idea as we have filesystem corruption issues
if you use one of the unofficial firmwares, you might be able to find something in the system folder, but no idea where, and it's probably some strange format file/etc, so very unrealistic that anyone could change it
you'd get further wanting a text to speech reader for dingux, at least then it's feasable (sp?)