[japper88]

Not everyone uses SPB Mobile Shell. For people still using Manila 2.1 (like me) you can't put shortcuts on the home screen (like in Manila 2.5). Having a physical button launch the camera is great for me. Another benefit is you can launch the camera from any window or app. Meaning if I'm using another program and I see something I quickly want to snap a pic of, I can just long press my volume up button get to the camera and just press the volume up button to snap the pic! Using the volume up button as a camera button is great because I can just flip the phone upside down and it feels just like a standard digi cam.