FWIW I do think that Apple acted reasonably given that they had three choices:

1. Give the UK a backdoor

2. Turn the feature off and hope that UK users complain to their government. Especially after the nudes start leaking en mass - nobody wants to see that :-)

3. Ignore the order. That would probably require closing all UK Apple Stores and evacuating all physical, financial and personnel assets from the UK - and from any jurisdiction that cooperates with the UK. Which basically means Earth.