John Gruber:

I think the current behavior of the iPhone mute switch is correct. You can’t design around every single edge case, and a new iPhone user who makes the reasonable but mistaken assumption that the mute switch silences everything, with an alarm set that he wasn’t aware of, and who is sitting in the front row of the New York Philharmonic when the accidental alarm goes off, is a pretty good example of an edge case.

I’m with John on this one. I bet it’s much more common for someone to fall asleep with an alarm set and the ringer switch set to off than it is for someone to have an alarm go off in an inopportune moment when they believed the ringer on/off switch would silence that alarm.

The design of the ringer on/off switch is by no means perfect, but it’s as close as you can get without adding unnecessary user confusion through extra prompts or potentially confusing options in the Settings app.