Upload & Sell: Off
I donít really use it that much but do sometimes for landscapes and tripod work just to set focus, otherwise I canít understand why you want to take a picture when not focusing. Maybe it depends on what you shoot?
Wildlife is a pretty common scenario where you don't want to keep refocusing. Especially birds or other creatures who hide among branches/trees/plants.
If I've, say, got a bird in a tree, I'm in a fixed position relative to the animal, but I may take 10+ shots trying to find the right pose or head position. My focus distance doesn't change, and having the camera refocus every time increases the probability that the focus will change and maybe I'll end up with the wing instead of the eye in focus, or a leaf that's intruding on the scene.
Also, it lets me not worry about small composition changes - since my next shot won't refocus, the placement of the focus point isn't critical.
And then, if you do want to keep focusing, you can. It just doesn't force the focus mechanism to be directly linked to your choice to release the shutter.