> Because you iphone is accessible on seconds notice anytime anywhere.

Not if I'm travelling internationally, as then I'm concerned about the implications of having border officials demand access to my phone. Or if I'm participating in various watersports/snowsports/backcountry activities where a phone is problematically fragile and difficult to keep charged.

In either of those scenarios (which account for the majority of pictures I take) I'm more likely to have a camera accessible than a phone.