Xbox One demos being on PC isn't a thing.
Are we are all aware Xbox 360 games were originally demoed on Power Mac G5’s, right? Can we spread that around the Internet like a virus, too? Or is that an exclusive right only Gaf and Reddit have? Don't go their for information. Especially when the fanboy wars are getting worse than they ever have been.
Devs are going to chose the most stable method of demoing their games. Right now, it’s a PC. Next year, One dev kits. There were plenty of PS4 controllers plugged into PC's to show off PS4 games. Like Gerstmann or not, he was there. Let's, you know, use our brains here.