The argument of the avilability of 'an alternative safer method' ie; wfp over ladder work, is a bit shallow really, especially for low level (say, up to 1st floor).
If we take driving a car as an example, crash helmets are accessible and available to everyone, and would reduce the number of serious head injuries that occur each year through accidents at the wheel, however nobody wears one, nor are we encouraged to.
Its all in the interpretation, risk assement and appropiateness / availability / accessability of safer alternatives in my book, but applying the risk assement correctly and making a mature decision based on the results is key.