While most aircraft types can do a 180 on a 45M wide runway it makes more sense to go to the end if you miss the turn off and turn on the turning circle as it gives you more room for error ( ie. less chance of a wheel in the mud) and is less stressful on the gear and tyres.
We fly into LTN regularly with A300s and usually make the turn off, but if it's wet and we are at max landing weight we sometimes go to the end. Again less stress on the aircraft and less wear on the brakes.