Based on some interaction with my S branded friends. The reason for them to get it is because iPhone's screen is too small. Not enough for them to view. And some of them said that the game size is small on phone but not enough resolution when played on iPad with 2x enlargement. Some say, it just boring to look at the phone design which almost identical every year.
I am not going to counter cos some of it are facts. But I just want to point out the bigger picture.
To people who think a phone can replace everything. Let dream about it and keep your S brand. To people who like to play game. App Store is having much more high quality and quantity games than google play. To people who think design are boring in apple. Think about those car brand like BMW, Audi, farrari.... They kept the same design in their range of car so that you can easily spot them.
If apple do not have it owns design taste. It is not apple anymore.
Anyway, apple just proved that gold color of phone can sell well too. Not like others who fail to achieve the target and trying to follow the trend.