Many people have voiced complains that they want to use touchID for applepay but not to have a passcode setup on their phone.
You cannot currently do that on stock firmware but maybe in the future there will be a hack available for that restriction. Nothing right now though.
I don't think that even "should" be possible. Mind giving my your key to the house too?
Jailbreaking is about giving the user full access and control of their device.
Your opinion that it should never be possible kinda goes against that. If you think its a bad idea or don't like it then you don't have to do it with your phone.
Others should have the option available if they want IMO.
