With that logic then, if I fire a rifle down main street at noon and nobody gets hurt, then it's okay? Simply because nobody has been hurt in the UK, this is empirical evidence? The nobody-got-hurt-yet argument is a poor one for lowering the bar
It's the CAAs logic not mine. We have had the NPPL since 2002, using medical declaration based on the requirements for a drivers licence. If you reach the standard for a truck or bus driver, you can carry passengers. If you only reach car driver standard, you can't carry passengers. There has not been an increase in incapacitiation amongst holders of the NPPL. The CAA spent a lot of time on analysis of the risks involved, before the system was introduced. Your system of " nobody got hurt for 70 years, but it must be dangerous" is hardly founded in logic.