To be fair, the real reason to release Mass Effect for the PC is that Bioware has a very significant worldwide fan base on the PC, cultivated with literally a decade of RPG goodness. Those PC fans buy their products and Bioware doesn't want to let them down so they keep buying Bioware products-like Dragon Age. Keeping your customer base engaged and purchasing things is a good thing in any industry.
GT5 on PC seems sort of strange because there's not really people frothing at the mouth for it and it's never been on the PC and has no fan base there. And if he wanted a PC game to sell to the Chinese, he'd have to do something totally different than GT5 for them.