Originally Posted by
Ziyyigo-Tipyigo
But even discounting that, there's Occam's Razor. The PS2 code was written nearly a year before the PC version, and even at launch it was cheaper and easier to port the PS2 version than to write a dedicated PC client from scratch.
Everything else being a port of the PS2 version also explains a lot of idiosyncrasies, like the separate RGB corrections in other versions as well as the many graphical glitches (e.g. airship jumping to the dock at the last second rather than docking smoothly) that do not occur in the PS2 version.
Insisting that the PC and Xbox clients were built from the ground up is like claiming the bailing wire, duck tape and Bondo are stock features. Technically possible, but... no.