More politely put, I see no obligation on employers to provide employees with the means to recharge their personal phones :)
This is a classic "design a better human" problem - sure, you can try to 'persuade' people by threatening them with demotions, suspensions and unemployment. And then you can hope that this will work in every single instance. Or ... you can provide a few usb ports in a convenient location, so people use these instead of the usb port in your multi million dollar cockpit to charge their phones. Take your pick.
For another example decide if it's easier to provide waste bins or to threaten people who litter streets.
Why would they NOT do this, under your system? If I can plug my phone in right where I am, in the cockpit, or somewhere less convenient for me, why would I not just do it where I am, in the cockpit? There are no penalties for it, so why wouldn't I do it?