Limited capacity devices is the way to go. Having large capacity, people will get too attached to their files and upgrade less often, which means less profit. Low capacity, is easy for people to move from one device to another and cost less to make.
Even andriod is abandoning their sd cards so people would not get attached to their current models.
Is like living space, you live in a small apartment with little stuff it's easy to move out, you live a big house, you'be put effort into organizing your garden, you've install heavy furniture and you've horde a ton of possessions, it is much harder to move again.
For me, I make use the cloud, I have 6x 2-3TB drives delivering media files whenever I want using air video, streamtome and audiogalaxy using unlimited 4G connection. My device hold 90% Apps.