Column projection/Technical query

Here IRC refers to International residential code

I somewhere read as follows:

You could also land a wooden column directly on a concrete footing. Let’s use a nominal 6x6. It measures 51/2 inches square, so the footing would project 91/4 inches beyond the 6x6. The projection exceeds the minimum 6-inch footing thickness, so to satisfy the IRC, this footing would have to be at least 91/4 inches thick. The reason is loads spread through a footing at 45 degrees in a cone shape (D). Concrete supported by the soil outside of this cone imposes a shear load on the footing, and such an unreinforced footing is likely to crack down the middle

If you understood and think that this is correct way, do you think that we all are following right technique?

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