Brand recognition pretty much. Most people who are dissappointed with the game went out a bought it on day 1 (I know I did). It's amazing what 25 years of strong tradition and solid games can do for people's expectations. That and the 5 years of hype, trailers and advertising.
Furthermore, how accurate is the difference you've posted in the title really? The PC sales are barely tracked (in fact, they are only tracked for Others and for only a few weeks after release). I know plenty of people bought the PC version but we don't have actual numbers. Theres also the PSN version to take into account.
The difference could be a lot less than 1.6 million.








