bitbydeath
Member
A huge amount of those sales are from the original PS3/360 versions. The PC version didn't exist to compete. There wasn't even an announcement for a PC version until much later, to prevent people holding off to get it later on. And when it was finally released it still had to share sales with the PS4/XBOXone versions and it still managed to sell as much as it did.
That’s still tens of millions more people choosing to rebuy the 30FPS edition over the 60FPS PC version.