I disagree with your statement. Even if all you do is use the camera in auto mode the ability of the better lens to let in more light will produce the better pi

I disagree with your statement. Even if all you do is use the camera in auto mode the ability of the better lens to let in more light will produce the better picture all other things being equal. If you also have a camera that has a larger light sensitive "film" area you will also get a better picture with the same inputs. Size is a factor in the enjoyment spectrum but the point-and-shoots do not have the clarity and depth that a decent digital SLR has and that is also a factor in how much you enjoy using your camera.