A major downfall [to some users] in iOS devices is the lack of expandable memory. In fact, that's generally one of the first things an Android-toting user would mention in a debate between the 2 popular breeds.
The iPhone comes in a 32GB, but that may not be enough space to lug around all of your files and media content. While even feature phones sport card readers nowadays, Apple has yet to include them in their lineup. So what if you want information on your SD card on your iPhone?