The problem is not unscrewing the hose clamp, it's forcing the hose onto the barb and getting it off again.
And you wouldn't do that to change keg, you would just move the QD from one keg to another.
'In theory' you don't need to detach your hoses from the disconnects, but it turns out that I am doing it all the time.
You also have the benefit of non kinked lines as the hose swivels 360 degrees in the adapter.