A big company like Sony wont have a surplus stock of anything, they'll be running a lean manufacturing/ordering system like every other manufacturer.Does/has Sony used the same Allwinner SoC in any other products? Either they had a surplus of them for some other product or they got offered a great deal. If Sony really wanted to win our hearts and minds, they would've used a MIPS SoC
The spec' of the SoC looks acceptable. It's a slow chip by todays standards, but should be more than powerful enough to run PS1 software with the right emulator.
I suspect something else has gone on behind the scenes.