Um, Avatar74, obviously I was referring to the home screen. I assume that's the purpose of having a number on the phone icon.
On that home screen, the only important item is if there is a waiting voicemail. All phones have some sort of symbol for this, Apple's is hidden because it may be a voicemail, or that number may be only a recent call.
Odd.
Actually that's kind of ergonomically smart...and I'm not saying that just to blow RDF up your butt. Think about this...
Whether you missed a call or a voicemail, either way you missed a call. Either you want to know what you missed or you don't... so what difference does it make?
Rather than cluttering the front display, they've alerted you to something that requires your attention. Go into the phone in one click and then see the detail of what you missed. How difficult is that?
The problem is that you can really clutter an interface just like you can clutter a Powerpoint presentation if you try to put EVERY level of information on one screen. I can't begin to tell you how quickly people get lost when idiots design powerpoint presentations that do not keep information hierarchically organized and instead put up bullet points with entire paragraphs that they read word-for-word. Same thing here... If you missed anything relating to phonecalls, iPhone tells you. One click takes you into more detail.
I'm a bit like that Dr. House guy on Fox who says "everybody lies." When someone tells you they want a tiny keyboard, do they really understand why, or what kind of convenience is it they're REALLY looking for and is there a better way to satisfy that need? The problem is that people are very bad at articulating what it is that truly makes them happy. Often they think in terms of features, but study after study after study shows its not individual bells and whistles but the overall user experience and design ergonomics that make the biggest impact in their overall satisfaction with a product.
People often say they want one thing, when in reality they are better satisfied/served by another, and even still do something else... I bet if you survey 100 people about the features and ask them if they think there should be two separate indicators, a majority will say yes. But if you survey the same 100 people and ask if they find it convenient and easy to have one indicator that alerts you to a missed call or voicemail, a majority will answer yes. The difference is in how the solution is presented (in this case, how the question is phrased). If you replace the words "are you satisfied" in a survey question with "how disssatisfied are you", and leave the rest of the question the same... watch what happens to the results!
And even still, if you put the phone in front of 100 people with an indicator showing a "1" in the phone, a majority will click the phone icon to find out what they missed... and they won't find it tremendously difficult or frustrating to do so because once they get there, the information is usefully and very clearly segregated in an immediately understandable way (what I said about the indicators being separated in the phone submenu).
Companies go down so many wrong corridors of design by listening to the first poorly conceived idea that is put forth without really getting at the root of the problem. If Apple stuck every indicator suggested on these boards onto the iPhone it would look like a freaking christmas tree riddled with lights and messages that no one can really make any sense from.
Keeping it organized makes it so easy to use that the time lost in pressing one freaking button is gained back tenfold by everything else that's ergonomically organized... not the least of which is the information in each detailed view of each missed call or voicemail.
For example: Even if caller ID is blocked (i.e. name not retrieved), did you notice that the detail view displays what city and state the call was from based on the area code? What if someone suggested we put this on the front screen because they thought it was useful? Sure it's useful... But the real issue is:
At what LEVEL in the hierarchy of information management is such information MOST useful?
Keeping data and information organized in nested hierarchies by level of goes a LONG way toward maximizing the user experience.