This allows a low current switch and light gauge wiring to be used. I wonder what the alternative would be?
One double BS1363 in my lounge is wired via a 20A switch in the normal light switch position by the door. I've no idea if it's a radial from the CU or a spur off a ring, but the previous owners were an American couple and outlets switched from wall-switches for lamps are ubiquitous in the US.