if we had to use single point AF for the camera to focus properly to achieve a sharp image, then what's the point of putting 61 pt. AF when it will be useless other than a maketing strategy. As far as I understood, those points when selected will be the basis of the camera to focus on regardless of other settings. What's the point of having zones or expansion points if focus cannot be achieved? Does this mean we will need to use the 61 points individually?
Well, more points could help you to avoid "focus and recompose". The problem with the 5DII focus points, is there weren't many and they were all clustered around the center of the VF. And more focus points could help with bright situations when using AI Servo with moving targets. It just depends on what you are shooting, and what AF mode you need to be in. For weddings, I normally use "one shot" drive mode, and might only switch to "AI-Servo" when bride is walking down aisle and that sort of thing.