The nature of the problem here is that when Apple first implemented the Wifi & Bluetooth toggle in Control Center way back in iOS 7, it was to turn it off. Now in iOS 11, they changed the behaviour of THE SAME BUTTON to merely disconnect and not turn off.
And this CHANGE wasn't immediately obvious to the average end user, NOR was it properly explained by Apple during their keynote, NOR stated in the change-log, NOR did Apple state it in a simple welcome screen when users first open an app after a major update.
Users were pretty much kept in the dark when they upgraded to iOS 11, and - for the less technologically-adept - it could take a while before they realise the change.
What they should've done when they decided to implement this was to change the look of the toggles in CC somehow to indicate its changed function, SO AS NOT TO mislead users into thinking it was serving the same function as before.
At the very least, Apple should've either 1) stated the change to users, or 2) make it obvious in the toggles that there's a new change to the toggle action, instead of forcing it upon them without any disclosure.
I don't think Apple would implement a 3D touch for the toggle to alternate between 'turn off' and 'disconnect', because that would go against the original action of 3D touching the toggle platter to access more controls.
Right now, I think Apple should just give users an option to choose the action of the Wifi & Bluetooth button in Settings.