That may be true if you assume the threat is a state actor or TLA. That's not the case here. A USB based method for resetting a device would be perfectly accept

That may be true if you assume the threat is a state actor or TLA. That's not the case here. A USB based method for resetting a device would be perfectly acceptable to use before sending in a device for repair. If you're worried about a state removing the flash chips to recover data from dead/used cells, you don't send your phone in for repair. You secure the data with a drill before disposing of it. That clearly wasn't the owner's concern. They wanted a method for securing the device, but couldn't due to the screen. This is in no way the owner's fault. I can't say I blame them wanting to have a working phone and not a very expensive paper weight. A better method for securely erasing data from a phone before service is in everyone's best interests. The customer's data isn't at risk, the manufacturer has significantly reduced liability, and the vendor doing the work doesn't have to worry about employees doing something stupid like this and risking their contract with Google. You really just have to make the process of getting the data off the phone slightly more difficult to avoid casual theft (infringement? -- I don't know the right word here).