Try plugging an Android phone into your PC and mounting it as a storage device. You'll have access to all the files and folders, just as you do when you browse through your WIndows computer's C drive. So, if you want to copy a raft of MP3s or PowerPoint presentations to your Android handset, you can just drag and drop them.
Say you record a memo with Droid Record and want to grab its output files. You can navigate down to its folder and move, copy or share them directly from there. If you run a file browser on the phone itself, you can also dive into the file system from there.
So what happens when you plug the iPhone 5 into your PC? You get access the digital camera (DCIM) folder only so all you can do is drag and drop pictures. Yes, you can iTunes to transfer media files back and forth, but you still can't go directly into file system because Apple just doesn't trust you enough to let you see the folders on the iPhone 5 that you bought from them. Whose phone is it anyway?