Just watching Rhod Gilbert on the C4 Comedy Gala moaning that his electrician placed 2 sockets the wrong way up......much hilarity ensued!
But the more I think of it, the more sense it makes in some places. My PC/laptops combo (my desk looks likes NASA!) would be much easier if the sockets were upside down. Lamps would be easier if the plugs sockets were upside down.
Or failing that, have the flex coming out of the top of the plug!