(why are UK people doing everything differently?)
it's older, it's grounded, safer and secure (ie. fits more securely and is harder to knock out), I believe the uk runs more power in the grid,
and the plug is easier to fit if you want to cut off the plug and fit another one. The fuse in there also protects you from damage in a power surge.
The EU two prongs don't have proper grounding and you can knock them out of the plug socket unless you use the massive kettle plugs that are more like the uk ones. Even a monkey like me can easily fit a UK plug with a knife and a screwdriver. That said europe is better than north america.
Next you'll be saying NTSC is better than PAL... bah!
ps. I'm in Spain so have the EU plugs which hurts my eletronics