The car has mechanisms, some of them implemented in software (eg turning on cooling fans) to not get hot. So does a switch. Someone installing gentoo on a car

The car has mechanisms, some of them implemented in software (eg turning on cooling fans) to not get hot. So does a switch. Someone installing gentoo on a cars ECU, and not implementing the feature to turn the fans on will easily overheat and destroy the car... the same is happening here with the lcd controller (and yes, the switch is designed so that the user can never go above some brightness level... unless the user hacks the switch and installs some random linux on it).