WHY?
Have you heard about "cloud" computing???? Why would I need a 64 GB phone when I can have a 100GB cloud service? Every user is different, and I listen to raw audio, so I HAVE to go to the cloud in order to get what I want. If your an MP3 fan, 16 GB's can supply MORE than you can listen to on a commute.
People with tiered data plans don't think like you do. Some of the movies I watch is 8gigs in size.