Bootloader unlock is under user control by definition - it won't happen unless you're physically interacting with the device. The legitimate case for safety net is platform lockdown for things like financial apps. Banks and other financial services like to provide some form of insurance to users wrt. losing money in a security breach, and they can't do this unless the app really is being run on a pristine, locked-down platform. Unfortunately it also impacts sillier things like media streaming and online video games. But the best way to cope with that is simply not to use those.