So since it's a "security issue", the only resort for Apple was to BRICK user's phone he paid huge amounts for? Why couldn't they just disable the entire finger

So since it's a "security issue", the only resort for Apple was to BRICK user's phone he paid huge amounts for? Why couldn't they just disable the entire fingerprint system (only) duly informing the user and restoring the phone to factory settings (erasing everything) at the most if needed?