Jason Snell reporting for Macworld:
I suspect, though, that inside Apple there was some skepticism about the iPhone SE’s potential audience. Perhaps people at Apple got a little carried away with that same bigger-is-better philosophy and lost perspective about why people might want a low-cost, small, full-featured iPhone.
That’s just speculation. What’s fact, based on what Apple CEO Tim Cook said on Tuesday, is that Apple blew it when it came to its forecasts for how well the iPhone SE would sell. Right now, “overwhelming demand” for the the iPhone SE means that Apple can’t make them fast enough—that used to happen all the time, but it’s been a while since Apple has been behind on iPhone supply.