The original poster seems to be fairly knowledgeable about the subject. Especially when you take into consideration the fact that they are using the correct terminology. That said the observation itself tells us next to nothing beyond the local picture. Space allocation is actually the result of market size, regional preferences, and overarching sales performance. Purchasing patterns depend a lot upon the region of where a retail location is placed. How many customers it is likely to service, and how much spending power those customers possess. Any retail chain that didn't take these things into consideration while planning their layouts would be courting disaster.
You are all fundamentally thinking in a provincial sense. Not just based on a regional perspective, but upon your own economic perspective. You don't actually accomplish anything by comparing stores within thirty miles of your house. Their layouts are a product of local trends and spending patterns. If you want to see the role of how where you live matters. Drive out to a market that is detached from your local market. If you live somewhere that is affluent. Then drive somewhere that is less affluent. If you live in a small city. Then drive to a store in a major urban center.
That all said I must say this. Don't for a moment take the total software sales on this site as the gospel truth. They have never proven to be reliable. Beyond the major titles where independent verification is available. For all any of us know this site could be over tracking these sales by over a hundred percent. If you don't have more then one source then you need to treat the data with a huge grain of salt.