In reply to Tom Valentine:
Some chefs will be coming at it from a gastronomic point of view, FSA will be coming at it purely from a public health point of view.
As others have said it should be possible to have meat safe and rare, but this is very hard to measure and control.
From a food safety point of view it is a lot easier to control and measure if you just say everything needs to be cooked throughout to 75c.