I'm not sure how you wanting to have 16 apps per folder as opposed to 12 means that you use your devices more than me... but aside from that, my point is that there just isn't enough room on the current iPhone. Open any folder with 9-12 apps and you will clearly see from the faded out apps that there isn't enough room for another row. You can argue Apple should squeeze them a little bit closer, or maybe by removing the rudundant space there may be enough room, but I personally think (and obviously Apple agrees) that would look a little crowded. Also, I like the size because you can press on the empty space above OR below the folder to "close" the folder. It's a subtle thing, and you probably don't even realize how much you appreciate it. My point is Apple made the folders that size for good reason, and I don't see them changing it. Now a 4" iPhone 5 on the other hand...